<p>Today's <strong>Image of the Day</strong> from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features the picturesque wetlands of Spain's Doñana National Park, This vital ecosystem, located in the Andalusia region, has received some long-awaited rainfall after enduring years of severe <a href="https://www.earth.com/news/climate-change-has-made-droughts-20-times-more-likely/" target="_blank" rel="noreferrer noopener">drought</a> conditions. </p>



<p>A significant increase in rainfall in March 2024 brought temporary relief to this UNESCO World Heritage Site and Biosphere Reserve, known for its rich biodiversity and critical role as a Ramsar Wetland of International Importance.</p>



<h2 class="wp-block-heading" id="h-a-decade-of-drought-in-donana-national-park">A decade of drought in Doñana National Park</h2>



<p>For over a decade, Doñana National Park has faced below-average rainfall levels, with the situation worsening significantly in the past three years. These years have recorded some of the lowest annual precipitation totals, compounded by unusually high temperatures across the country.&nbsp;</p>



<p>The effects of <a href="https://www.earth.com/news/drought-to-downpour-climate-change-triggers-extreme-weather-shifts/" target="_blank" rel="noreferrer noopener">climate change</a> were starkly visible in January 2024, which was noted as Spain's warmest January since records began, with temperatures averaging 2.4 degrees Celsius higher than normal.</p>



<p>The first quarter of 2024 continued this trend, potentially marking it as the warmest first quarter since 1961. The prolonged <a href="https://www.earth.com/news/global-drought-crisis-un-warns-of-unprecedented-emergency/" target="_blank" rel="noreferrer noopener">drought</a> has had a devastating impact on the park’s ecosystem, drying up <a href="https://www.earth.com/news/nearly-all-of-the-worlds-salt-marshes-may-be-underwater-by-2100/" target="_blank" rel="noreferrer noopener">marshes</a> and affecting both flora and fauna.</p>



<h2 class="wp-block-heading" id="h-welcome-change-in-the-weather">Welcome change in the weather</h2>



<p>The heavy rains that arrived in late March 2024 have momentarily brought some relief to the region. Satellite images acquired by the OLI on Landsat 8 and the OLI-2 on Landsat 9 showed significant changes in the landscape by April 9, 2024.&nbsp;</p>



<p>The featured image shows that marshes have been replenished and ponds have been temporarily filled, contrasting sharply with the desolate conditions observed just a year earlier.</p>



<p>A weather station in the park recorded 145 millimeters of rainfall in March 2024, making it the second-wettest March on record. Since the start of the water year in September 2023, the area has received over 400 millimeters of rainfall, surpassing the totals of each of the last three full water years. Despite this increase, the precipitation still falls short of the historical yearly average of more than 500 millimeters.</p>



<h2 class="wp-block-heading" id="h-ecological-responses-and-challenges">Ecological responses and challenges</h2>



<p>The western part of the park is home to thousands of small, shallow pools known as Mediterranean temporary ponds, which naturally experience cycles of flooding and drying. Following the recent rains, several of the largest ponds flooded, as did marsh areas farther inland, though some regions remained dry.</p>



<p>The Doñana Biological Station reported that this influx of water led to a resurgence of vegetation beneficial to breeding waterfowl such as coots, grebes, and herons.&nbsp;</p>



<p>However, despite these positive signs, the challenges remain significant. Development pressures from agricultural fields and an adjacent resort town continue to strain the local aquifer, exacerbating the water scarcity and impacting the wetland's ecological balance.</p>



<h2 class="wp-block-heading" id="h-long-term-concerns-for-donana-national-park">Long-term concerns for Doñana National Park</h2>



<p>Javier Bustamante, a researcher at the Doñana Biological Station, emphasized that while the rainfall has eased some of the immediate drought-related issues, it does not address the deeper problem of groundwater overexploitation.&nbsp;</p>



<p>"The rains have partially alleviated the most immediate drought problems, but they do not solve the invisible problem of groundwater overexploitation," Bustamante stated, highlighting the complex nature of the challenges facing Doñana.</p>



<p>The overall effect of the rainfall will become clearer in the coming months, but experts caution that the changes observed might not signify long-term relief. Conservation efforts continue to focus on managing external pressures and restoring the ecological balance to preserve Doñana National Park for future generations.</p>



<h2 class="wp-block-heading" id="h-more-about-donana-national-park">More about Doñana National Park</h2>



<p>Doñana National Park is one of Europe's most important and diverse natural reserves. This vast park stretches across parts of the provinces of Huelva, Seville, and Cádiz. It was established as a national park in 1969 and covers an area of approximately 543 square kilometers.</p>



<p>The park is celebrated for its extraordinary biodiversity. It serves as a critical stopover, breeding, and wintering site for thousands of European and African migratory birds.&nbsp;</p>



<p>Doñana's complex ecosystem includes <a href="https://www.earth.com/news/coastal-wetlands-are-inching-closer-to-extinction-as-the-world-heats-up/" target="_blank" rel="noreferrer noopener">marshlands</a>, shallow streams, and sand dunes, providing habitat for a wide variety of plant and animal species. Among its notable inhabitants are the Iberian lynx and the Spanish imperial eagle, both of which are endangered species.</p>



<p>Doñana also has a rich cultural heritage; it has been influenced by various civilizations throughout history, including the Romans and Moors. This history is reflected in the archaeological sites found within its boundaries, including the remains of the town of La Algaida.</p>



<p>Image Credit: NASA Earth Observatory&nbsp;</p>



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Doñana National Park gets temporary relief from drought

Today's Image of the Day from NASA Earth Observatory features...

<p>Today's <strong>Image of the Day</strong> from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features Ruang, a small volcanic island in North Sulawesi, Indonesia. The tranquil environment of Ruang was shattered by a powerful volcanic eruption on the night of April 16, 2024.</p>



<p>This event has left the island's 800 residents grappling with its devastating aftermath, while scientists are assessing its potential global effects.</p>



<h2 class="wp-block-heading" id="h-a-violent-awakening-on-ruang">A violent awakening on Ruang</h2>



<p>Ruang, located in the Sangihe Islands arc, is known for its long history of <a href="https://www.earth.com/news/volcanic-eruptions-play-an-overlooked-role-in-earths-climate/" target="_blank" rel="noreferrer noopener">volcanic activity</a>, but the intensity of the latest eruption has been particularly alarming. The <a href="https://www.earth.com/news/explosive-volcanic-eruption-triggered-an-hours-long-thunderstorm/" target="_blank" rel="noreferrer noopener">eruption</a> produced explosive discharges, sending vast plumes of ash and gas soaring into the stratosphere. The force of nature transformed lush greenery into a gray wasteland.</p>



<p>“Late on April 16, 2024, the mountain roared to life, unleashing a series of explosive eruptions that, at times, sent plumes of ash and gas billowing high into the stratosphere. The eruption also bombarded the island with tephra, small pebbles of lapilli, and fine shards of pulverized rock called ash,” said NASA.</p>



<h2 class="wp-block-heading" id="h-extensive-damage-and-humanitarian-efforts">Extensive damage and humanitarian efforts</h2>



<p>The eruption's immediate impact was severe, with settlements on the north side of Ruang and Laingpatehi village experiencing extensive damage due to volcanic debris.&nbsp;</p>



<p>More than 500 houses were destroyed or severely damaged, according to Indonesia’s disaster management agency, Badan Nasional Penanggulangan Bencana (BNPB). The heavy ashfall also impacted local agriculture, damaging crops and farms.&nbsp;</p>



<p>In response to the crisis, the Sam Ratulangi International Airport in nearby Manado was temporarily closed, disrupting travel and causing widespread flight cancellations. It was not until April 22 that the airport could reopen, following significant cleanup efforts and a decrease in the volcanic threat level.</p>



<h2 class="wp-block-heading" id="h-scientific-analysis-and-global-concerns">Scientific analysis and global concerns</h2>



<p>The eruption has attracted significant scientific interest due to the vast quantities of ash and sulfur dioxide it emitted. Atmospheric scientist Ghassan Taha from NASA’s Goddard Space Flight Center noted, "We expect to see aerosol particles circulating in the stratosphere for weeks, if not months." This observation is critical as particles reaching this altitude can have extensive, albeit temporary, effects on global climate patterns.</p>



<p>Volcanologist Simon Carn from Michigan Technological University reported that the eruption released between 0.3 to 0.5 teragrams of sulfur dioxide on April 17 and 18. These levels, while substantial, fall below the threshold generally required to affect global temperatures significantly.&nbsp;</p>



<p>For context, the 1991 Mount Pinatubo eruption, which had a pronounced cooling effect on the Earth's climate, released approximately 20 teragrams of sulfur dioxide.</p>



<h2 class="wp-block-heading" id="h-preparedness-and-future-risks">Preparedness and future risks</h2>



<p>In light of Ruang's active volcanic history and the potential for further eruptions, local authorities remain vigilant. The risk of lahars and tsunamis prompted immediate evacuations and multiple tsunami warnings, though, fortunately, no substantial tsunamis have occurred thus far. Over 16,000 residents have been evacuated from the most vulnerable areas, a move that has likely prevented any fatalities or serious injuries.</p>



<p>The 2024 <a href="https://www.earth.com/news/underwater-volcanic-eruptions-are-more-harmful-than-previously-believed/" target="_blank" rel="noreferrer noopener">eruption</a> of Ruang is a stark reminder of the powerful and often unpredictable nature of volcanic islands. While the local and immediate impacts are devastating, the eruption also offers valuable data for scientists studying the broader implications of such natural events on atmospheric conditions and climate. </p>



<h2 class="wp-block-heading" id="h-more-about-ruang">More about Ruang</h2>



<p>The population on Ruang is small, with residents primarily engaged in subsistence fishing and agriculture, which is typical of remote Indonesian islands. The island's terrain and soil fertility, influenced by volcanic ash, may support the cultivation of certain crops that are adapted to such conditions.</p>



<p>The Ruang volcano rises to about 725 meters above sea level, making it a prominent feature in the region. This area is part of the volcanic arc that includes numerous volcanoes produced by the subduction of the oceanic plate under the continental margin.</p>



<p>The active stratovolcano has had several recorded eruptions in history, with significant activity occurring in 1871, 1873, and 2002.&nbsp;</p>



<p>The image was captured by the Operational Land Imager (OLI) on April 20, 2024.</p>



<p>Image Credit: NASA Earth Observatory&nbsp;</p>



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Ruang volcano eruption has devastated the tranquil island

<p>Today's <strong>Image of the Day</strong> from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features the Bermejo River and the Río Grande de Tarija, which flow through Argentina and Bolivia in South America. The photograph was captured by an astronaut onboard the International Space Station.</p>



<h2 class="wp-block-heading" id="h-meandering-rivers">Meandering rivers</h2>



<p>“The meandering rivers in this image are sourced in the Andes Mountains and generally flow southeast through valleys in the foothills - the region between the high mountains and plains. The Iruya River deposits particles of silt and clay as it flows into the valley centered in this image,” said NASA.</p>



<p>“Visible indications of the rivers’ shifting channels include river islands, point bars (on the inside curve of streams), and several meander scars. Such scars form when a river gets cut off from the main flow and fills in with sediment, soil, and vegetation.”</p>



<p>“Sediment from the adjacent highlands filled valleys that were formed by tectonic forces driving uplift of the Andes. These deposits are subsequently carried by rivers, such as the Iruya, along with new sediment to form the light-toned braided channels and the adjacent darker-toned floodplains. Nutrient-rich floodplain soils provide fertile ground for agricultural fields.”</p>



<h2 class="wp-block-heading" id="h-bermejo-river">Bermejo River</h2>



<p>The Bermejo River originates in the Bolivian <a href="https://www.earth.com/news/biodiversity-hotspots-are-shrinking-in-the-andes-mountains/" target="_blank" rel="noreferrer noopener">Andes</a> and flows into Argentina. It plays a crucial role in the geographical and ecological landscape of the region. The river's course is characterized by its meandering path through the Gran Chaco plain, making it a significant river in the region's hydrological system.</p>



<h3 class="wp-block-heading" id="h-economic-importance">Economic importance</h3>



<p>The Bermejo River is vital for agriculture, providing essential water resources for irrigation. It also has potential for hydroelectric power generation.</p>



<h3 class="wp-block-heading" id="h-biodiversity-nbsp">Biodiversity&nbsp;</h3>



<p>The diverse habitats created by the Bermejo River, including its riverbanks, floodplains, and adjacent forests, support rich biodiversity. However, the wildlife in this region faces threats from habitat destruction, pollution, and climate change, making conservation efforts critical for their survival.</p>



<p><a href="https://www.earth.com/news/jaguars-in-the-amazon-are-threatened-by-climate-extremes/" target="_blank" rel="noreferrer noopener">Jaguars</a> are the apex predators of this region, and are occasionally spotted along the riverbanks, where they hunt. Large, herbivorous mammals called tapirs are found in the forests around the Bermejo River. They often visit the river to drink and cool off.</p>



<p>Capibaras, the world’s largest rodents, are commonly found in the wetlands and along the river edges.</p>



<p>The tallest flying bird found in South and Central America, jabirus can often be seen in wetlands along the Bermejo River. Toco toucans, known for their colorful bills, can be found in the forested areas near the river.</p>



<h2 class="wp-block-heading" id="h-rio-grande-de-tarija">Río Grande de Tarija</h2>



<p>The Río Grande de Tarija, also known in its lower stretches as the Guadalquivir, flows primarily within Bolivia. It is a critical watercourse in the Tarija Department, contributing significantly to the region's agriculture and livelihoods.</p>



<h3 class="wp-block-heading" id="h-economic-importance-0">Economic importance</h3>



<p>This river is essential for irrigation, supporting a variety of crops and contributing to the local economy. The surrounding lands are fertile and productive, thanks to the river's water.</p>



<h3 class="wp-block-heading" id="h-challenges">Challenges</h3>



<p>Similar to other rivers, the Río Grande de Tarija faces challenges such as water management issues, <a href="https://www.earth.com/news/predicting-the-effects-of-pollutants-on-river-ecosystems/" target="_blank" rel="noreferrer noopener">pollution</a>, and the impacts of climate change on its flow and health.</p>



<h3 class="wp-block-heading" id="h-wildlife-in-bolivian-rivers">Wildlife in Bolivian rivers</h3>



<p>River basins in Bolivia are home to a wide range of bird species, including various species of herons, egrets, kingfishers, and perhaps even some rarer species like the wattled jacana or the sunbittern. The diverse birdlife is attracted to the abundance of fish and the relatively untouched natural habitats along the river.</p>



<p>The Characidae family includes many fish species that are commonly found in South American rivers, such as tetras. They are known for their diversity and are a key part of the river's ecosystem, serving as both <a href="https://www.earth.com/news/diving-to-extremes-predatory-fish-frequent-the-oceans-twilight-zone/" target="_blank" rel="noreferrer noopener">predator</a> and prey.</p>



<p>Cichlids are another diverse group of fish that can be found in South American rivers. They are appreciated by aquarium enthusiasts worldwide and play significant roles in their ecosystems as both predators and herbivores.</p>



<p>The rivers of Bolivia are also home to various catfish species, which are well adapted to life in muddy and turbulent waters. These include the armored catfish, which are often found clinging to rocks and logs.</p>



<p>Image Credit: NASA Earth Observatory/ ISS Crew Earth Observations Facility/ Earth Science and Remote Sensing Unit, Johnson Space Center</p>



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<h3 class="wp-block-heading" id="h-nbsp">&nbsp;</h3>

The Río Grande de Tarija and Bermejo River in South America

<p>Today's <strong>Image of the Day</strong> from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features the delta of the Ebro River on the northeast coast of Spain, captured by the Copernicus Sentinel-2 mission.</p>



<h2 class="wp-block-heading" id="h-ebro-river">Ebro River</h2>



<p>“Stretching across 910 km of northern Spain, the Ebro River is the second-longest river in the Iberian Peninsula. In the image, it can be seen as a green line winding its way through the peninsula before flowing into the Mediterranean, shaping the Ebro Delta,” noted ESA.</p>



<p>“The Ebro River discharges more water into the sea than any other river in Spain. As suspended sediment flows from the river’s mouth, it tints the coastal waters with a turquoise hue.”</p>



<h2 class="wp-block-heading" id="h-ebro-delta">Ebro Delta</h2>



<p>The Ebro Delta is one of the largest <a href="https://www.earth.com/news/wetland-methane-emissions-have-surged-at-high-latitudes/">wetland areas</a> in the western Mediterranean region. The river's basin is the largest in Spain, covering about 85,000 square kilometers.</p>



<h2 class="wp-block-heading" id="h-historical-significance-nbsp">Historical significance&nbsp;</h2>



<p>Historically, the Ebro River has been significant in numerous battles, including the famous Battle of the Ebro during the Spanish Civil War, which was one of the war's longest and deadliest conflicts.&nbsp;</p>



<h2 class="wp-block-heading" id="h-economic-significance-nbsp">Economic significance&nbsp;</h2>



<p>Economically, the Ebro plays a crucial role in agriculture, particularly in regions like La Rioja and Navarre, which are known for their vineyards. Additionally, the river supports various industries and hydroelectric power generation.</p>



<h2 class="wp-block-heading" id="h-ecological-significance">Ecological significance</h2>



<p>The Ebro Delta is ecologically rich, providing habitat for diverse bird species. It is also a vital area for rice cultivation in Spain.&nbsp;</p>



<h3 class="wp-block-heading" id="h-nature-reserve">Nature reserve</h3>



<p>“Most of the delta comprises the Ebro Delta Nature Reserve. With its protected wetlands, beaches, marshes, salt pans and estuaries, this reserve provides a natural habitat for numerous migratory birds and waterfowl,” said ESA.</p>



<h3 class="wp-block-heading" id="h-environmental-challenges-nbsp">Environmental challenges&nbsp;</h3>



<p>The river and its delta face environmental challenges such as pollution, water extraction for irrigation, and the impacts of <a href="https://www.earth.com/news/climate-change-may-have-altered-river-flow-worldwide/">climate change</a>, which threaten its ecosystem and the sustainability of its water resources.</p>



<h2 class="wp-block-heading" id="h-the-northeast-coast-of-spain">The northeast coast of Spain</h2>



<p>The northeast coast of Spain is a vibrant and diverse region, characterized by its rich history, unique culture, and stunning landscapes. </p>



<p>It includes the autonomous communities of Catalonia, which features the dynamic city of Barcelona, and part of the Valencian Community. This area is also part of what is known as the Costa Brava, which stretches from the town of Blanes up to the French border.</p>



<h3 class="wp-block-heading" id="h-geography">Geography</h3>



<p>The <a href="https://www.earth.com/news/human-activity-impacts-97-percent-of-the-worlds-coastline/">coastline</a> is renowned for its rugged beauty, with rocky cliffs, secluded coves, and small beaches. The interior regions feature mountains such as the Pyrenees, which offer skiing in winter and hiking in the summer.</p>



<h3 class="wp-block-heading" id="h-cultural-heritage">Cultural heritage</h3>



<p>The area has a strong cultural identity, particularly in Catalonia, where there is a significant movement for independence. The Catalan language is widely spoken alongside Spanish. The region is also known for its festivals, architecture (notably the works of Antoni Gaudí in Barcelona), and traditional dances like the Sardana.</p>



<h3 class="wp-block-heading" id="h-cuisine">Cuisine</h3>



<p>The cuisine is a delightful mix of fresh seafood from the Mediterranean, traditional Catalan dishes like "pa amb tomàquet" (bread with tomato), and rice dishes such as paella in the Valencian region. The area is also famous for its wines, including the sparkling wine Cava.</p>



<h3 class="wp-block-heading" id="h-tourism">Tourism</h3>



<p>The northeast coast attracts millions of tourists each year due to its beautiful beaches, historical sites, and vibrant cities. Barcelona, in particular, is a major tourist destination with attractions like the Sagrada Familia, Park Güell, and the bustling La Rambla.</p>



<h3 class="wp-block-heading" id="h-economy">Economy</h3>



<p>The economy of the northeast coast is one of the most dynamic in Spain, with Barcelona serving as a major hub for trade, education, entertainment, and technology.</p>



<p>Image Credit: NASA Earth Observatory</p>



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The Ebro River on the northeast coast of Spain

<p>Today's <strong>Image of the Day</strong> from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features the United Arab Emirates, where a slow-moving storm system dumped more than a year's worth of rainfall in just a few hours. </p>



<p>“The UAE’s National Center for Meteorology reported that eastern parts of the country measured up to 250 millimeters (10 inches) of rain in less than 24 hours. UAE, known for its dry desert climate, receives only about 140 to 200 millimeters (5.5 to 8 inches) of rainfall per year,” said NASA.</p>



<p>“Dubai International Airport recorded 119 millimeters on April 16, which is 1.5 times its typical annual rainfall. The deluge temporarily halted flights at the airport, which is among the world’s busiest for international travel.”</p>



<h2 class="wp-block-heading" id="h-heaviest-rainfall-on-record-in-the-united-arab-emirates-nbsp">Heaviest rainfall on record in the United Arab Emirates&nbsp;</h2>



<p>Authorities noted that this was the heaviest <a href="https://www.earth.com/news/record-heat-fueled-unexpected-and-deadly-storms-in-2023/" target="_blank" rel="noreferrer noopener">rainfall</a> on record in the United Arab Emirates. The news agency WAM called it a historic weather event that surpassed “anything documented since the start of data collection in 1949.”&nbsp;</p>



<p>“Heavy rain triggered flash flooding across eastern parts of the country, inundating roads and disrupting transportation,” said NASA. “The system first hit Oman on April 14 and continued to batter the UAE through most of the day on April 16.”&nbsp;</p>



<p>At least 18 people were killed in the <a href="https://www.earth.com/news/heavy-rainfall-events-in-the-northeast-are-set-to-increase-by-over-50-percent/" target="_blank" rel="noreferrer noopener">heavy rains</a> in Oman, including ten children that were swept away in a vehicle with one adult, according to a statement from the country’s National Committee for Emergency Management.&nbsp;</p>



<h2 class="wp-block-heading" id="h-strong-low-pressure-system">Strong low-pressure system</h2>



<p>Michael Mann, a climate scientist at the University of Pennsylvania, noted that three low-pressure systems formed a train of <a href="https://www.earth.com/news/thunderstorms-are-becoming-more-intense-due-to-climate-change/" target="_blank" rel="noreferrer noopener">storms</a> slowly moving along the jet stream - the river of air that moves weather systems - toward the Persian Gulf.&nbsp;</p>



<p>“The strong low-pressure system delivered multiple rounds of high winds and heavy rain to the northern and eastern parts of the country,” said NASA. “Some areas remained flooded on April 19, when Landsat 9 passed over the region for the first time since the storms.”&nbsp;</p>



<p>Climate experts attribute such extreme weather events to <a href="https://www.earth.com/news/limiting-global-warming-to-1-5-degrees-celsius-would-save-billions-of-lives/" target="_blank" rel="noreferrer noopener">global warming</a>. According to a report from Reuters, researchers anticipate that climate change will lead to hotter temperatures, increased humidity, and a greater risk of <a href="https://www.earth.com/news/seeking-ways-to-prevent-flooding-caused-by-climate-change/" target="_blank" rel="noreferrer noopener">flooding</a> in parts of the Gulf region. “Countries like the UAE where there is a lack of drainage infrastructure to cope with heavy rains can suffer the most,” the report stated.&nbsp;</p>



<h2 class="wp-block-heading" id="h-more-about-the-united-arab-emirates-nbsp">More about the United Arab Emirates&nbsp;</h2>



<p>The United Arab Emirates (UAE) is a federation of seven emirates located on the eastern side of the Arabian Peninsula. It borders Oman and Saudi Arabia, and has maritime borders with Iran and Qatar in the Persian Gulf. Established as a federation in 1971, the UAE has rapidly developed into one of the most modern and wealthy nations in the world, largely thanks to its vast oil and natural gas reserves.</p>



<p>Abu Dhabi serves as the capital and is the largest emirate, both in terms of land area and economy, largely because it holds the majority of the UAE's oil reserves. Dubai is the most populous city and is renowned globally for its spectacular skyscrapers, including the Burj Khalifa, the tallest building in the world, as well as its bustling ports, and vibrant tourism and shopping sectors.</p>



<p>The UAE has a diverse and multicultural society with a significant expatriate population, drawn by business opportunities and the tax-free living in many sectors. The official language is Arabic, though English is widely spoken, especially in business and educational settings.</p>



<p>Politically, the UAE is a federal absolute monarchy. It is governed by a Supreme Council of Rulers made up of the seven emirs, who appoint the prime minister and the cabinet. The country has made significant strides in terms of infrastructure and healthcare, and it continues to invest heavily in various sectors including renewable energy, education, and technology.</p>



<p>Culturally, the UAE balances its rapid modernization with a strong commitment to traditional Arab culture. The heritage of the desert Bedouin lifestyle is celebrated with falconry, camel racing, and traditional dance remaining integral to its cultural festivities. The nation is also a major hub for international arts and sports events, enhancing its global profile and cultural footprint.</p>



<p>Image Credit: NASA Earth Observatory&nbsp;</p>



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Storms dumped record rainfall in the United Arab Emirates

Earth,Core,Structure.,Elements,Of,This,3d,Image,Furnished,By

<p>In a remarkable discovery that challenges our understanding of Earth's <a href="https://www.earth.com/news/pumping-too-much-groundwater-affects-earths-spin/" target="_blank" rel="noreferrer noopener">water distribution</a>, aided by a mineral called ringwoodite, researchers found evidence suggesting the presence of several oceans worth of water trapped deep beneath the United States. </p>



<p>The discovery, made by geophysicist Steve Jacobsen from <a href="https://www.northwestern.edu/" target="_blank" rel="noreferrer noopener">Northwestern University</a> and seismologist Brandon Schmandt from the <a href="https://www.unm.edu/" target="_blank" rel="noreferrer noopener">University of New Mexico</a>, may represent the planet's largest water reservoir. </p>



<h2 class="wp-block-heading" id="h-rethinking-earth-s-water-cycle">Rethinking Earth's water cycle</h2>



<p>Published in the journal <em>Science</em>, their findings shed light on the Earth's formation, composition, and the amount of water trapped in mantle rock.</p>



<p>"Geological processes on the Earth's surface, such as <a href="https://www.earth.com/news/earthquakes-have-long-lasting-impacts-on-forests/" target="_blank" rel="noreferrer noopener">earthquakes</a> or erupting volcanoes, are an expression of what is going on inside the Earth, out of our sight," explained Jacobsen, a co-author of the paper. </p>



<p>"I think we are finally seeing evidence for a whole-Earth <a href="https://www.earth.com/news/temperature-fluctuations-have-reshaped-earths-water-cycle/" target="_blank" rel="noreferrer noopener">water cycle</a>, which may help explain the vast amount of liquid water on the surface of our habitable planet. Scientists have been looking for this missing deep water for decades," Jacobsen continued.</p>



<h2 class="wp-block-heading" id="h-earth-s-mantle-has-remarkable-secrets">Earth's mantle has remarkable secrets</h2>



<p>Scientists have long speculated about the existence of water trapped in the <a href="https://www.earth.com/news/earths-mantle-may-contain-a-wealth-of-green-metals/" target="_blank" rel="noreferrer noopener">Earth's mantle</a>, located between the lower and upper mantle at depths of 250 to 410 miles. </p>



<p>Jacobsen and Schmandt are the first to provide direct evidence of water in this "transition zone" on a regional scale, extending across most of the interior of the United States.</p>



<p>"Melting of rock at this depth is remarkable because most melting in the mantle occurs much shallower, in the upper 50 miles," said Schmandt, a co-author of the paper. </p>



<p>"If there is a substantial amount of H2O in the transition zone, then some melting should take place in areas where there is flow into the lower mantle, and that is consistent with what we found."</p>



<h2 class="wp-block-heading" id="h-liquid-ice-vapor-and-a-fourth-form-of-water">Liquid, ice, vapor and a fourth form of water</h2>



<p>The water discovered in the mantle is not in a form familiar to us – it is not liquid, ice, or vapor. Instead, it is trapped inside the molecular structure of the minerals in the mantle rock. </p>



<p>The immense pressure created by 250 miles of solid rock, along with temperatures above 2,000 degrees Fahrenheit, causes water molecules to split and form hydroxyl radicals (OH) that can be bound into a mineral's crystal structure.</p>



<p>"Whether or not this unique sample is representative of the Earth's <a href="https://www.earth.com/news/theia-ancient-planet-buried-inside-of-earth-may-be-the-origin-of-our-moon/" target="_blank" rel="noreferrer noopener">interior composition</a> is not known, however," Jacobsen said. "Now we have found evidence for extensive melting beneath North America at the same depths corresponding to the dehydration of ringwoodite, which is exactly what has been happening in my experiments."</p>



<h2 class="wp-block-heading" id="h-following-the-ringwoodite">Following the ringwoodite</h2>



<p>Ringwoodite, a high-pressure mineral with a captivating blue hue, was named after the Australian geologist Alfred Ringwood, forms deep within the Earth's mantle at depths between 410 and 660 kilometers (250-410 miles). What makes ringwoodite truly remarkable is its ability to store water within its crystal structure.</p>



<h3 class="wp-block-heading" id="h-synthesizing-ringwoodite-in-the-lab">Synthesizing ringwoodite in the lab</h3>



<p>Jacobsen has been synthesizing ringwoodite, a sapphire-like blue mineral, in his Northwestern lab by reacting the green mineral olivine with water at high-pressure conditions. He found that more than one percent of the weight of ringwoodite's crystal structure can consist of water.</p>



<p>Under the immense pressures and temperatures found in the mantle's transition zone, water molecules split into hydroxyl radicals (OH), which can then be incorporated into ringwoodite's structure. This mineral acts like a sponge, soaking up water and storing it in the <a href="https://www.earth.com/news/discovery-ancient-ocean-floor-surrounds-the-earths-core/" target="_blank" rel="noreferrer noopener">deep Earth</a>.</p>



<p>"The ringwoodite is like a sponge, soaking up water," Jacobsen said. "There is something very special about the crystal structure of ringwoodite that allows it to attract hydrogen and trap water. This mineral can contain a lot of water under conditions of the deep mantle."</p>



<h3 class="wp-block-heading" id="h-ringwoodite-implications-for-earth-s-formation-and-habitability">Ringwoodite implications for Earth's formation and habitability</h3>



<p>The presence of water-rich ringwoodite in the Earth's mantle has implications for our understanding of the planet's formation and its potential for habitability.</p>



<p>As scientists continue to study this intriguing mineral, they may uncover new insights into the role of water in the Earth's deep interior and its influence on the geologic processes that shape our world.</p>



<p>Ringwoodite's ability to store and transport water within the <a href="https://www.earth.com/news/earths-ancient-breath-study-links-atmospheric-oxygen-and-mantle-chemistry/" target="_blank" rel="noreferrer noopener">mantle</a> could also have implications for the search for life on other planets, as the presence of water is considered a key factor in the development and sustainability of life as we know it.</p>



<h2 class="wp-block-heading" id="h-detecting-magma-beneath-north-america">Detecting magma beneath North America</h2>



<p>Using seismic waves, Schmandt detected the presence of magma beneath North America, which aligned with Jacobsen's findings of partial melt when subjecting synthesized ringwoodite to conditions around 400 miles below the Earth's surface.</p>



<p>Additionally, seismic studies have detected regions of partial melting in the mantle's transition zone, which could be attributed to the release of water from ringwoodite as it transforms into other minerals at greater depths.</p>



<p>"Seismic data from the USArray are giving us a clearer picture than ever before of the <a href="https://www.earth.com/news/earths-interior-is-cooling-faster-than-previously-thought/" target="_blank" rel="noreferrer noopener">Earth's internal structure</a> beneath North America," Schmandt explained. "The melting we see appears to be driven by subduction -- the downwelling of mantle material from the surface."</p>



<h2 class="wp-block-heading" id="h-process-of-dehydration-melting">Process of dehydration melting</h2>



<p>The melting detected by the researchers is called dehydration melting. When ringwoodite in the transition zone moves deeper into the lower mantle, it forms a higher-pressure mineral called silicate <a href="https://www.earth.com/news/perovskite-crystals-appear-to-dance-when-they-get-excited/" target="_blank" rel="noreferrer noopener">perovskite</a>, which cannot absorb water. This causes the rock at the boundary between the transition zone and lower mantle to partially melt.</p>



<p>"When a rock with a lot of H2O moves from the transition zone to the lower mantle it needs to get rid of the H2O somehow, so it melts a little bit," Schmandt said. "This is called dehydration melting."</p>



<p>"Once the water is released, much of it may become trapped there in the transition zone," Jacobsen added.</p>



<h2 class="wp-block-heading" id="h-how-ringwoodite-was-accidentally-discovered">How ringwoodite was accidentally discovered</h2>



<p>The international team of scientists responsible for this remarkable find was led by Graham Pearson, Canada Excellence Research Chair in Arctic Resources at the <a href="https://www.ualberta.ca/index.html" target="_blank" rel="noreferrer noopener">University of Alberta</a>. </p>



<p>Analysis of the mineral sample revealed that it contains a significant amount of water -- 1.5 per cent of its weight -- a finding that proved to have far-reaching implications for our understanding of the Earth's interior and its dynamic nature.</p>



<h3 class="wp-block-heading">Elusive ringwoodite</h3>



<p>Ringwoodite, a form of the mineral peridot, is believed to exist in large quantities under high pressures in the transition zone between the Earth's upper and lower mantle. </p>



<p>While ringwoodite has been found in meteorites, no terrestrial sample had ever been discovered before Graham Pearson came along. Due to the extreme depths at which it is formed, this elusive mineral is inaccessible for direct fieldwork.</p>



<h3 class="wp-block-heading" id="h-contribution-of-artisan-miners-in-brazil">Contribution of artisan miners in Brazil</h3>



<p>The ringwoodite sample was found in 2008 in the Juina area of Mato Grosso, Brazil, where artisan miners unearthed a <a href="https://www.earth.com/news/mystery-of-how-diamonds-reach-the-earths-surface-finally-solved/" target="_blank" rel="noreferrer noopener">diamond</a> from shallow river gravels. </p>



<p>The diamond, which had been brought to the Earth's surface by a deeply derived volcanic rock known as kimberlite, contained the ringwoodite inclusion.</p>



<p>Pearson's team had been searching for another mineral when they purchased the three-millimeter-wide, dirty-looking, commercially worthless brown diamond. </p>



<p>The ringwoodite itself, invisible to the naked eye and buried beneath the surface, was fortunately discovered by Pearson's graduate student, John McNeill, in 2009.</p>



<p>"It's so small, this inclusion, it's extremely difficult to find, never mind work on," Pearson said, "so it was a bit of a piece of luck, this discovery, as are many scientific discoveries."</p>



<h3 class="wp-block-heading">Confirming the Find</h3>



<p>The sample underwent years of rigorous analysis using Raman and infrared spectroscopy and X-ray diffraction before it was officially confirmed as ringwoodite. </p>



<p>The critical water measurements were performed at Pearson's Arctic Resources Geochemistry Laboratory at the University of Alberta, which forms part of the world-renowned <a href="https://www.eas.ualberta.ca/ccim/" target="_blank" rel="noreferrer noopener">Canadian Centre for Isotopic Microanalysis</a>, also home to the world's largest academic diamond research group.</p>



<h2 class="wp-block-heading">Implications for Earth's Dynamics</h2>



<p>For Pearson, one of the world's leading authorities in the study of deep Earth diamond host rocks, this discovery proved to be the most significant of his career. </p>



<p>It confirmed about 50 years of theoretical and experimental work by geophysicists, seismologists, and other scientists trying to understand the makeup of the Earth's interior.</p>



<p>"One of the reasons the Earth is such a dynamic planet is the presence of some water in its interior," Pearson said. "Water changes everything about the way a planet works."</p>



<h2 class="wp-block-heading" id="h-ringwoodite-earth-s-water-cycle-and-the-future">Ringwoodite, Earth's water cycle, and the future</h2>



<p>In summary, the crucial discovery of a vast water reservoir deep within the Earth's mantle by Steve Jacobsen and Brandon Schmandt has revolutionized our understanding of the planet's formation, composition, and water cycle.</p>



<p>As researchers continued to explore the complex processes occurring far beneath the Earth's surface, their ringwoodite findings provided a new understanding of the delicate balance that makes our planet habitable. </p>



<p>The presence of this hidden ocean, trapped within the crystals of mantle rock, serves as a testament to the incredible forces at work within the Earth and the countless mysteries that still lie beneath our feet. </p>



<p>With each new revelation, we move closer to unraveling the secrets of our planet's past, present, and future, and to appreciating the remarkable world we call home.</p>



<p>The full study was published in the journal <em><a href="http://www.sciencemag.org/" target="_blank" rel="noreferrer noopener">Science</a> </em>and the journal<em> <a href="http://www.nature.com/nature/journal/v507/n7491/full/nature13080.html" target="_blank" rel="noreferrer noopener">Nature</a></em></p>



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Earth has a vast interior ocean, 400-miles under our feet, that creates 'ringwoodite' gems

In a remarkable discovery that challenges our understanding of Earth's...

<p>As we continue to explore the cosmos, we are discovering an increasing number of exoplanets that could potentially <a href="https://www.earth.com/news/nasa-finds-17-exoplanets-that-have-oceans-and-possibly-alien-life/" target="_blank" rel="noreferrer noopener">harbor life</a>. One such world is K2-18 b, an exoplanet that has recently captured the attention of astronomers due to the presence of intriguing DMS gas molecules in its atmosphere.</p>



<h2 class="wp-block-heading" id="h-carbon-footprints-found-on-k2-18-b">Carbon footprints found on K2-18 b</h2>



<p>In September 2023, Nikku Madhusudhan, an astronomer at the <a href="https://www.cam.ac.uk/" target="_blank" rel="noreferrer noopener">University of Cambridge</a>, announced a <a href="https://www.earth.com/news/does-exoplanet-k2-18-have-the-right-conditions-to-support-alien-life/" target="_blank" rel="noreferrer noopener">very intriguing discovery</a>. </p>



<p>Using the powerful James Webb Space Telescope (<a href="https://webb.nasa.gov/" target="_blank" rel="noreferrer noopener">JWST</a>), Madhusudhan and his team detected the presence of carbon-bearing molecules, including methane and carbon dioxide, on exoplanet K2-18 b. </p>



<p>This discovery was added to other <a href="https://hubblesite.org/contents/news-releases/2019/news-2019-50" target="_blank" rel="noreferrer noopener">recent studies</a> suggesting that K2-18 b could be a Hycean exoplanet, characterized by a hydrogen-rich atmosphere and a water ocean-covered surface.</p>



<p>"Our findings underscore the importance of considering diverse habitable environments in the search for life elsewhere," explained Madhusudhan, the lead author of the paper announcing these results. </p>



<p>"Traditionally, the search for life on exoplanets has focused primarily on smaller rocky planets, but the larger <a href="https://www.earth.com/news/new-class-of-exoplanets-discovered/" target="_blank" rel="noreferrer noopener">Hycean worlds</a> are significantly more conducive to atmospheric observations," he continued.</p>



<h2 class="wp-block-heading" id="h-tantalizing-hint-of-dimethyl-sulfide-dms">Tantalizing hint of dimethyl sulfide (DMS)</h2>



<p>The initial Webb observations also provided a possible detection of a molecule called dimethyl sulfide (DMS). On Earth, this molecule is "only produced by life", primarily by <a href="https://www.earth.com/news/plankton-tiny-ocean-creatures-overlooked-critical-life-on-earth/" target="_blank" rel="noreferrer noopener">phytoplankton</a> in marine environments. </p>



<p>The abundance of methane and carbon dioxide, along with the shortage of ammonia, support the hypothesis that K2-18 b may have a water ocean underneath a hydrogen-rich atmosphere.</p>



<p>"It was a real shock, I had sleepless nights for a week," enthused Dr. Madhusudhan, recalling the moment when the analysis showed a possible hint of DMS in the planet's atmosphere. "That week, I didn't even muster the courage to break it to my own team."</p>



<h2 class="wp-block-heading" id="h-why-a-whiff-of-dms-made-astronomers-look-again">Why a whiff of DMS made astronomers look again</h2>



<p>Dimethyl sulfide (DMS) is an organic compound with the chemical formula (CH3)2S. This colorless, flammable liquid possesses a characteristic odor often associated with the smell of the ocean. </p>



<p>DMS plays a crucial role in the Earth's sulfur cycle and has garnered significant attention due to its potential as a biomarker for extraterrestrial life.</p>



<h3 class="wp-block-heading" id="h-biological-significance-of-dms-on-earth">Biological significance of DMS on Earth</h3>



<p>On Earth, dimethyl sulfide is predominantly produced by marine organisms, particularly <a href="https://www.earth.com/news/marine-plankton-hold-a-long-record-of-ocean-health/" target="_blank" rel="noreferrer noopener">phytoplankton</a>. These tiny, photosynthetic organisms release DMS as a byproduct of their metabolic processes. </p>



<p>When DMS enters the atmosphere, it undergoes oxidation, contributing to the formation of cloud condensation nuclei. This process influences cloud formation and, consequently, Earth's climate.</p>



<h3 class="wp-block-heading">DMS as a biomarker for extraterrestrial life</h3>



<p>Detecting DMS on distant exoplanets presents numerous challenges. The molecule's spectral signature is difficult to distinguish from other compounds, and its presence in an atmosphere may be masked by other gases. </p>



<p>The detection of DMS in the atmosphere of an exoplanet, such as K2-18 b, has significant implications for the search for extraterrestrial life. </p>



<p>On Earth, DMS is exclusively produced by biological processes, making it a compelling biomarker. The presence of DMS in an exoplanet's atmosphere suggests the possibility of marine life similar to Earth's <a href="https://www.earth.com/news/rising-temperatures-may-flip-plankton-into-carbon-emitters/" target="_blank" rel="noreferrer noopener">phytoplankton</a>.</p>



<h2 class="wp-block-heading" id="h-k2-18-b-an-exoplanet-like-no-other">K2-18 b: An exoplanet like no other</h2>



<p>K2-18 b orbits the cool dwarf star K2-18 in the <a href="https://www.earth.com/news/study-expands-the-habitable-zone-where-we-may-find-alien-life/" target="_blank" rel="noreferrer noopener">habitable zone</a>, approximately 120 light-years from Earth in the constellation Leo. With a radius 2.6 times that of Earth, K2-18 b is unlike anything in our solar system. </p>



<p>These <a href="https://www.earth.com/news/neptune-like-exoplanets-atmospheres-interesting-earth-size-neighbors/" target="_blank" rel="noreferrer noopener">sub-Neptune exoplanets</a> are poorly understood, and the nature of their atmospheres is a matter of active debate among astronomers.</p>



<p>"Although this kind of planet does not exist in our solar system, sub-Neptunes are the most common type of planet known so far in the galaxy," explained team member Subhajit Sarkar of <a href="https://www.cardiff.ac.uk/" target="_blank" rel="noreferrer noopener">Cardiff University</a>. </p>



<p>"We have obtained the most detailed spectrum of a habitable-zone <a href="https://www.earth.com/news/planetary-migration-model-explains-super-earths-and-sub-neptunes/" target="_blank" rel="noreferrer noopener">sub-Neptune</a> to date, and this allowed us to work out the molecules that exist in its atmosphere," Sarkar concluded.</p>



<h2 class="wp-block-heading" id="h-cosmic-detective-story-continues">Cosmic detective story continues</h2>



<p>The team is now conducting follow-up research with the JWST's <a href="https://webb.nasa.gov/content/observatory/instruments/miri.html" target="_blank" rel="noreferrer noopener">MIRI</a> (Mid-Infrared Instrument) spectrograph, hoping to further validate their findings and provide new insights into the environmental conditions on K2-18 b. </p>



<p>The inference of DMS on the exoplanet, though incredibly tantalizing, requires further validation. As Madhusudhan explained, "Upcoming Webb observations should be able to confirm if DMS is indeed present in the atmosphere of K2-18 b at significant levels."</p>



<p>"Our ultimate goal is the identification of life on a <a href="https://www.earth.com/news/super-earth-discovered-in-the-habitable-zone-of-its-star/" target="_blank" rel="noreferrer noopener">habitable exoplanet</a>, which would transform our understanding of our place in the universe," concluded Madhusudhan. "Our past findings and future studies are a promising step towards a deeper understanding of Hycean worlds in this quest."</p>



<h2 class="wp-block-heading" id="h-implications-of-finding-life-on-k2-18-b">Implications of finding life on K2-18 b</h2>



<p>As we stand on the precipice of a potentially transformational discovery, the tantalizing hint of alien life on K2-18 b reminds us of the boundless possibilities that await us in the vast expanse of the universe. </p>



<p>The tireless efforts of astronomers like Nikku Madhusudhan and his team, coupled with the unparalleled capabilities of the Webb Telescope, bring us closer than ever to answering one of humanity's most profound questions: Are we alone? </p>



<p>As we eagerly anticipate the upcoming observations and the revelations they may bring, we find ourselves inspired by the relentless curiosity and unwavering dedication of those who seek to unravel the mysteries of the cosmos, pushing the boundaries of our understanding and redefining our place in the universe.</p>



<p>The full study was published in <em><a href="https://iopscience.iop.org/journal/2041-8205" target="_blank" rel="noreferrer noopener">The Astrophysical Journal Letters</a></em>.</p>



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Webb studies planet K2-18 b again to confirm presence of gas ‘only produced by life’

As we continue to explore the cosmos, we are discovering...

<p>A team of biologists led by the <a href="https://uol.de/en" target="_blank" rel="noreferrer noopener">University of Oldenburg</a> in Germany has recently made significant strides in understanding how <a href="https://www.earth.com/news/migratory-birds-have-new-strategy-to-cope-with-climate-change/" target="_blank" rel="noreferrer noopener">migratory birds</a> navigate with remarkable accuracy. </p>



<p>The research, which also included experts from the <a href="https://ifv-vogelwarte.de/en/home" target="_blank" rel="noreferrer noopener">Institute of Avian Research “Vogelwarte Helgoland”</a>, was focused on the role of a specific protein in birds’ eyes, believed to be a key magnetoreceptor enabling this navigation. </p>



<h2 class="wp-block-heading" id="h-genetic-basis-of-how-birds-navigate-nbsp">Genetic basis of how birds navigate&nbsp;</h2>



<p>The researchers compared the genomes of several hundred bird species and observed notable evolutionary changes in the gene encoding the protein cryptochrome 4. They found that certain groups of birds have completely lost this gene.&nbsp;</p>



<p>“This suggests that the protein is important for adaptation to specific environmental conditions,” said senior author Miriam Liedvogel, the director of the Institute of Avian Research. “A similar pattern has been observed in other sensory proteins such as light-sensitive pigments in the eye.”</p>



<h2 class="wp-block-heading" id="h-magnetoreception-in-birds">Magnetoreception in birds</h2>



<p>Previous research revealed that magnetoreception in birds is linked to a complex quantum mechanical process in the <a href="https://www.earth.com/news/rare-retinal-cells-explain-complex-color-perception/" target="_blank" rel="noreferrer noopener">retina</a>. </p>



<p>For instance, a 2021 study suggested cryptochrome 4 as the probable magnetoreceptor, showing that it is present in the retina and responds to magnetic fields with a quantum effect, an ability more pronounced in robins than in non-migratory birds like chickens and pigeons.</p>



<p>“Consequently, the reason why cryptochrome 4 is more sensitive in robins than in chickens and pigeons must be found in the protein’s DNA sequence,” explained lead author Corinna Langebrake, a researcher at the Institute of Avian Research. “The sequence was probably optimized by evolutionary processes in these nocturnal migratory birds.”</p>



<h2 class="wp-block-heading" id="h-the-role-of-cryptochrome-4">The role of cryptochrome 4</h2>



<p>In the current study, the team examined the cryptochrome 4 genes across 363 bird species, from the little spotted kiwi to the song sparrow.&nbsp;</p>



<p>They compared the evolutionary rate of cryptochrome 4 with that of other related proteins and found that while other cryptochromes have changed little over time due to their crucial role in regulating the <a href="https://www.earth.com/news/internal-clock-living-human-cells/" target="_blank" rel="noreferrer noopener">internal clock</a>, cryptochrome 4 showed high variability. This variability suggests a specialized function, potentially as a magnetoreceptor. </p>



<p>“A similar pattern has been observed in other sensory proteins such as light-sensitive pigments in the eye,” Liedvogel said. Particularly among passerine birds, the protein appears to have undergone rapid selection, further supporting its specialized role in magnetoreception.</p>



<h2 class="wp-block-heading" id="h-alternative-mechanisms-of-magnetoreception">Alternative mechanisms of magnetoreception</h2>



<p>Interestingly, the study also found that three clades of tropical birds - <a href="https://www.earth.com/news/saving-parrots-in-the-illegal-wildlife-trade-with-dna-technology/" target="_blank" rel="noreferrer noopener">parrots</a>, hummingbirds, and Tyranni (suboscines), known as tyrants - have lost the gene for cryptochrome 4, indicating it may not be essential for their survival. </p>



<p>Since some tyrants are long-distance migrants, their lack of cryptochrome 4 presents an opportunity to explore alternative mechanisms of magnetoreception.</p>



<h2 class="wp-block-heading" id="h-do-some-birds-navigate-without-any-magnetic-sense">Do some birds navigate without any magnetic sense?</h2>



<p>“The fact that, unlike robins, they do not have cryptochrome 4 makes them an ideal system for investigating various hypotheses about magnetoreception,” Langebrake explained.&nbsp;</p>



<p>A key question is whether the Tyranni have evolved a magnetic sense that functions without the cryptochrome 4 protein, or if they can navigate without relying on any magnetic sense at all.&nbsp;</p>



<p>Additionally, it's possible that their magnetic sensing capabilities mirror those found in robins, which rely on light and can be influenced by external factors such as radio waves.</p>



<p>“The first two scenarios would strongly corroborate the cryptochrome 4 hypothesis, while the third would pose a problem for the theory,” she added.</p>



<h2 class="wp-block-heading" id="h-magnetoreception-and-bird-navigation-nbsp">Magnetoreception and bird navigation&nbsp;</h2>



<p>Moving forward, the research team plans to investigate magnetic orientation in Tyranni to better understand the function of cryptochrome 4 and its importance in magnetoreception among migratory birds.&nbsp;</p>



<p>This research not only deepens our understanding of <a href="https://www.earth.com/news/birds-magnetic-field-navigate/" target="_blank" rel="noreferrer noopener">avian navigation</a> but also opens new avenues for exploring evolutionary adaptations in sensory perception.</p>



<h2 class="wp-block-heading" id="h-more-about-how-birds-navigate-nbsp">More about how birds navigate&nbsp;</h2>



<p>Migratory birds have remarkable abilities to navigate across vast distances, often traveling thousands of miles between breeding and wintering grounds. Their navigation skills are attributed to a variety of mechanisms:</p>



<h3 class="wp-block-heading" id="h-sun-compass">Sun compass</h3>



<p>Birds use the sun as a compass. They can gauge the time of day and adjust their flight direction based on the sun's position in the sky.</p>



<h3 class="wp-block-heading" id="h-star-compass">Star compass</h3>



<p>During night migration, many birds use the stars to navigate. They can identify constellations and use them to maintain their flight path.</p>



<h3 class="wp-block-heading" id="h-geomagnetic-field">Geomagnetic field</h3>



<p>Birds are sensitive to Earth's geomagnetic field. They have magnetoreceptors that allow them to sense magnetic fields, which helps them determine their latitude and longitude for orientation.</p>



<h3 class="wp-block-heading" id="h-polarized-light-patterns">Polarized light patterns</h3>



<p>Birds can detect polarized light patterns in the sky, which are most prominent at sunrise and sunset. These patterns can help calibrate their internal compasses.</p>



<h3 class="wp-block-heading" id="h-landmarks">Landmarks</h3>



<p>For birds that fly at lower altitudes, physical landmarks like rivers, mountains, and coastlines can serve as guides.</p>



<h3 class="wp-block-heading" id="h-olfactory-cues">Olfactory cues</h3>



<p>Some research suggests that certain birds may also use olfactory cues - smelling their way along their migration routes.</p>



<p>The study is published in the journal <a href="http://dx.doi.org/10.1098/rspb.2023.2308" target="_blank" rel="noreferrer noopener"><em>Proceedings of the Royal Society B: Biological Sciences</em></a><em>.</em></p>



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How do migratory birds navigate with such accuracy?

A team of biologists led by the University of Oldenburg...

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<p><br />
<span style="font-weight: 400;">Today&#8217;s </span><b>Video of the Day</b><span style="font-weight: 400;"> from </span><a href="https://www.nasa.gov/goddard"><span style="font-weight: 400;">NASA&#8217;s Goddard Space Flight Center</span></a><span style="font-weight: 400;"> reveals that Arctic sea ice likely reached its 2019 minimum extent of 1.6 million square miles on September 18.</span></p>
<p><span style="font-weight: 400;">According to NASA and the National Snow and Ice Data Center, this year&#8217;s minimum is tied for second lowest summertime extent in the satellite record.</span></p>
<p><span style="font-weight: 400;">Every year, the Arctic sea ice cap expands during the fall and winter and shrinks during the spring and summer months. In recent decades, however, warming temperatures have caused marked decreases across all seasons. </span></p>
<p><span style="font-weight: 400;">&#8212;</span></p>
<p><i><span style="font-weight: 400;">By </span></i><a href="http://csexton@earth.com"><i><span style="font-weight: 400;">Chrissy Sexton</span></i></a><i><span style="font-weight: 400;">, </span></i><a href="https://www.earth.com/staff/"><i><span style="font-weight: 400;">Earth.com</span></i></a><i><span style="font-weight: 400;"> Staff Writer</span></i></p>
<p><i><span style="font-weight: 400;">Video Credit: NASA&#8217;s Goddard Space Flight Center</span></i></p>
<p>&nbsp;</p>

Arctic sea ice shrinks to near-record low