<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

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 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

<p>Today's <strong>Image of the Day</strong> from the <a href="https://www.esa.int/" target="_blank" rel="noreferrer noopener">European Space Agency </a>features the barred spiral galaxy NGC 3783, which is located about 130 million light-years away in the constellation Centaurus. NGC 3783 is also the most prominent of a galaxy group (by the same name) that contains 47 <a href="https://www.earth.com/news/james-webb-captures-galaxies-that-are-too-old-to-exist/" target="_blank" rel="noreferrer noopener">galaxies</a>. </p>



<h2 class="wp-block-heading" id="h-galaxy-groups">Galaxy groups</h2>



<p>“Like galaxy clusters, galaxy groups are aggregates of gravitationally bound galaxies. Galaxy groups, however, are less massive and contain fewer members than <a href="https://www.earth.com/news/titanic-galaxy-cluster-collision-defies-all-current-understanding-of-the-universe/" target="_blank" rel="noreferrer noopener">galaxy clusters</a> do: where galaxy clusters can contain hundreds or even thousands of constituent galaxies, galaxy groups do not typically include more than 50,” noted ESA.</p>



<p>“The Milky Way is actually part of a galaxy group, known as the Local Group, which contains two other large galaxies (Andromeda and the Triangulum galaxy), as well as several dozen satellite and dwarf galaxies.”</p>



<h2 class="wp-block-heading" id="h-hd-101274-a-blue-giant-star">HD 101274: A blue giant star</h2>



<p>The bright object that appears to the right of the galaxy is the star HD 101274. “The perspective in this image makes the star and the galaxy look like close companions, but this is an illusion. HD 101274 lies only about 1,530 light-years from Earth, meaning it is about 85 thousand times closer than NGC 3783,” explained ESA.&nbsp;</p>



<p>HD 101274 is part of the NGC 3766 cluster, which is sometimes referred to as the Pearl Cluster, an open cluster known for its richness in bright stars and its relatively young age.</p>



<p>HD 101274 is categorized as a blue giant star, characterized by its high temperature and luminosity. Blue giants are massive stars that have left the main sequence phase of stellar evolution and are burning helium or heavier elements in their cores. These stars are known for their short lifespans relative to smaller stars due to their rapid consumption of nuclear fuel.</p>



<p><a href="https://www.earth.com/news/dark-stars-scientists-discover-a-new-type-of-star-powered-by-dark-matter/" target="_blank" rel="noreferrer noopener">Stars</a> like HD 101274 are important for astronomers because they help in studying the properties of stellar populations in clusters and the dynamics of stellar evolution in different environments. The spectral and photometric observations of such stars can provide valuable insights into the characteristics of their atmospheres, internal structures, and the processes occurring within and around them.</p>



<h2 class="wp-block-heading" id="h-bright-central-region-of-ngc-3783">Bright central region of NGC 3783</h2>



<p>One of the most interesting aspects of NGC 3783 is that it harbors an active galactic nucleus, meaning its central region is exceptionally luminous, likely due to the presence of a supermassive black hole. This black hole is actively accreting material, which emits a substantial amount of radiation as it spirals inward and heats up.</p>



<p>This galaxy is particularly known for its bright central region and has been studied extensively in the ultraviolet and X-ray light spectra to understand better the properties of the accretion disk around the black hole and the complex dynamics of the material surrounding it. These studies are crucial for understanding the physics of active galactic nuclei and the role they play in <a href="https://www.earth.com/news/galaxies-like-our-own-milky-way-are-not-unique/" target="_blank" rel="noreferrer noopener">galaxy evolution</a>.</p>



<p>According to ESA, NGC 3783 is a Type I Seyfert galaxy. “In this image it is recorded by Hubble in incredible detail, from its glowing central bar to its narrow, winding arms and the dust threaded through them, thanks to five separate images taken in different wavelengths of light," noted ESA.</p>



<p>“In fact, the galactic center is bright enough to Hubble that it exhibits diffraction spikes, normally only seen on stars such as HD 101274.”</p>



<h2 class="wp-block-heading" id="h-more-about-the-ngc-3783-galaxy-group">More about the NGC 3783 galaxy group</h2>



<p>The NGC 3783 group is part of the larger Hydra-Centaurus Supercluster, which itself is a massive collection of galaxies and galaxy clusters located primarily in the constellations of Hydra and Centaurus.</p>



<p>The NGC 3783 group consists of several galaxies that are gravitationally bound and interact with each other. These interactions can influence the galaxies' evolution through mechanisms like tidal forces and merger events, which can trigger star formation, fuel central black holes, and reshape the galaxies' structures.</p>



<p>Studying groups like the NGC 3783 group helps astronomers understand how <a href="https://www.earth.com/news/ceers-2112-ancient-galaxy-looks-strikingly-similar-to-ours/" target="_blank" rel="noreferrer noopener">galaxies</a> evolve together in a common gravitational environment, offering insights into the dynamics and evolution of structures on cosmic scales. This is especially relevant in understanding how galaxies influence each other through gravitational interactions and the environmental effects on galaxy evolution.</p>



<p>Image Credit: ESA/Hubble &amp; NASA</p>



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The luminous galaxy NGC 3783 and a blue giant star

Today's Image of the Day from the European Space Agency...

<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 sediment swirling in the Gulf of Alaska on December 29, 2023.</p>



<p>"After an unusually snowy start to winter, southern Alaska’s coastline remained under a blanket of white in late December," said NASA.</p>



<p>"Meanwhile, greens and tans swirled in the dark blue water offshore. The dullness of the hues near shore suggests that the water is mostly colored by sediment. It is likely that phytoplankton - microscopic plant-like organisms - contributed to some of the hues farther from the coast."</p>



<p>According to NASA, much of the sediment in this region comes from “glacial flour” carried into the gulf by the Copper River.&nbsp;</p>



<p>"Glacial flour forms as glaciers move over bedrock and grind it into a fine silt. When suspended in water, glacial flour can make the water appear an opaque turquoise color - similar to phytoplankton blooms. The sediment carries iron and other nutrients that can spur the growth of these tiny marine organisms," explained NASA.</p>



<p>Aimee Neeley, a biological oceanographer at NASA’s Goddard Space Flight Center, noted that there are always phytoplankton in the water, but usually at lower levels in the wintertime at these latitudes.</p>



<p>The Gulf of Alaska is a vast and biologically rich body of water that lies at the northernmost part of the Pacific Ocean, encircled by Alaska.&nbsp;</p>



<p>The gulf extends approximately 1,500 miles from the Alaska Peninsula and the Aleutian Islands in the west to the Alexander Archipelago in the east.</p>



<p>Characterized by a subarctic climate, it's known for heavy rain and <a href="https://www.earth.com/news/sea-ice-loss-increases-snowfall-over-west-antarctica/">snowfall</a>. The region is also prone to frequent storms and is a significant pathway for colder northern weather patterns moving into the United States.</p>



<p>The Gulf of Alaska is home to a diverse marine ecosystem. It supports many species of fish, such as salmon and halibut, and is also a habitat for marine mammals like whales, sea lions, and seals.</p>



<p>The image was captured by the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument on NASA’s Aqua satellite.</p>



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



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Sediment swirling in the Gulf of Alaska

<p>For centuries, desert travelers have relied on oases as life-giving sanctuaries. These pockets of green have sustained communities, fueled trade, and sparked imaginations. Yet, <a href="https://www.earth.com/news/thriving-reefs-oases-corals/" target="_blank" rel="noreferrer noopener">oases</a> are under pressure. New research exposes the delicate balance between human intervention and natural forces such as <a href="https://www.earth.com/news/pastoralists-desertification-sahara/" target="_blank" rel="noreferrer noopener">desertification</a> shaping the fate of these vital ecosystems.</p>



<h2 class="wp-block-heading" id="h-what-is-an-oasis">What is an oasis?</h2>



<p>An oasis isn't simply a desert mirage. It's a distinct, well-defined area where vegetation thrives, contrasting sharply with the surrounding arid landscapes. This extraordinary phenomenon is made possible by a dependable water source, which could be:</p>



<ul>
<li><strong>Groundwater:</strong>&nbsp;Underground water that reaches the surface, creating a natural spring or well.</li>



<li><strong>Mountain runoff:</strong>&nbsp;Water from rain or melting snow that flows down from higher elevations, gathering in low-lying desert areas.</li>
</ul>



<p>Despite covering only a tiny fraction (around 1.5%) of our planet's land area, oases play a disproportionately important role. They provide essential resources and support around 10% of the world's population, offering a lifeline in otherwise harsh, dry environments.</p>



<h2 class="wp-block-heading" id="h-human-efforts-to-expand-oasis">Human efforts to expand oasis</h2>



<p>Recent research offers a surprising insight into the changing nature of oases. Counterintuitively, between 1995 and 2020, the total area of oases worldwide increased by a staggering 85,000 square miles. While this might seem like a positive development, there's a crucial caveat. </p>



<p>The majority of this expansion is not a natural phenomenon but the result of deliberate human intervention. Here's how it happens:</p>



<h3 class="wp-block-heading" id="h-large-scale-irrigation-projects">Large-scale irrigation projects</h3>



<p>Governments and private entities embark on ambitious projects to divert water from rivers, lakes, or drill deep wells to tap into underground aquifers. This water is then channeled into desert regions, transforming them into artificially-created oases.</p>



<h3 class="wp-block-heading" id="h-water-intensive-agriculture">Water-intensive agriculture</h3>



<p>The primary objective of many artificial <a href="https://www.earth.com/image/heart-shaped-oasis-on-the-nile-river/" target="_blank" rel="noreferrer noopener">oases</a> is to support agriculture in otherwise barren areas. This involves growing crops that may not be naturally suited to arid environments, leading to high water demands.</p>



<h3 class="wp-block-heading" id="h-urbanization-and-development">Urbanization and development</h3>



<p>In some cases, artificial oases are created to support urban growth or industrial development in desert regions. These projects often require substantial and ongoing water resources.</p>



<p>However, the crucial issue with artificial oasis expansion lies in its potential unsustainability. These projects often rely on water sources that are either finite or overexploited. </p>



<h2 class="wp-block-heading" id="h-desertification-and-oases">Desertification and oases</h2>



<p>On the flip side, a relentless process called <a href="https://www.earth.com/earthpedia-articles/desertification/" target="_blank" rel="noreferrer noopener">desertification</a> poses a severe threat to oases. Desertification is the gradual transformation of fertile land into barren desert, often caused by factors such as climate change, overgrazing, and unsustainable water use. Desertification has led to the loss of approximately 52,000 square miles of oases during the same 25-year period.</p>



<p>“Although the scientific community has always emphasized the importance of oases, there has not been a clear map of the global distribution of oases,” said Dongwei Gui, a geoscientist at the <a href="https://english.cas.cn" target="_blank" rel="noreferrer noopener">Chinese Academy of Science</a> who led the study.</p>



<p>“Oasis research has both theoretical and practical significance for achieving United Nations Sustainable Development Goals and promoting sustainable development in arid regions.”</p>



<h2 class="wp-block-heading" id="h-net-result-of-desertification-precarious-oases-growth">Net result of desertification: Precarious oases growth</h2>



<p>At first glance, the expansion of oases might seem like a promising development – a victory against harsh desert conditions. However, a closer examination paints a far more complex and worrying picture. While the total area of oases has increased by approximately 33,400 square miles, this net growth masks a deeper problem. </p>



<p>Much of the recent growth in oasis areas is a direct result of artificial expansion projects. These human-made oases mask simultaneous losses of natural oases due to <a href="https://www.earth.com/news/sand-and-dust-storms-have-become-unpredictable-and-dangerous/" target="_blank" rel="noreferrer noopener">desertification</a>.</p>



<p>Many artificial oases depend on unsustainable water practices. This includes tapping into rapidly depleting groundwater sources or diverting water from ecosystems that rely on those rivers or lakes for their own survival. It's a trade-off, sacrificing one area for the short-term growth of another.</p>



<p>This reliance on unsustainable water use casts a long shadow on the future of these oases. As water resources dwindle and ecosystems are disrupted, the artificial expansion will become increasingly difficult to maintain. The very existence of these oases becomes precarious.</p>



<p>The net growth figure, while seemingly positive, hides a troubling reality. It underscores the delicate and vulnerable nature of these ecosystems and raises serious questions about whether this artificial expansion is simply a short-term solution with potentially devastating long-term consequences.</p>



<h2 class="wp-block-heading" id="h-why-do-we-save-oases-from-desertification">Why do we save oases from desertification?</h2>



<p>Oases serve as irreplaceable havens in the world's drylands. They:</p>



<h3 class="wp-block-heading" id="h-provide-essential-water">Provide essential water</h3>



<ul>
<li><strong>Drinking and domestic needs:</strong>&nbsp;Oases serve as primary water sources for communities living within them, fulfilling basic human needs.</li>



<li><strong>Farming:</strong>&nbsp;Irrigation from oases enables agriculture even in arid regions, providing food and supporting local economies.</li>



<li><strong>Livestock:</strong>&nbsp;Oases provide water to animals raised for sustenance or livelihood, crucial for pastoral and nomadic populations.</li>



<li><strong>Industry and development:</strong>&nbsp;Some oases support small-scale industries or other development projects that depend on access to water.</li>
</ul>



<h3 class="wp-block-heading" id="h-support-biodiversity">Support biodiversity</h3>



<ul>
<li><strong>Unique habitats:</strong>&nbsp;Oases create distinct micro-ecosystems within harsh desert environments, allowing specialized plants and animals to flourish.</li>



<li><strong>Endemic species:</strong>&nbsp;Some oases harbor plants and animals found nowhere else on Earth, contributing to global biodiversity.</li>



<li><strong>Migratory stopovers:</strong>&nbsp;Oases act as vital resting and refueling points for migratory birds and other wildlife traveling through arid regions.</li>
</ul>



<h3 class="wp-block-heading" id="h-offer-resilience-against-climate-change">Offer resilience against climate change</h3>



<ul>
<li><strong>Buffers against drought:</strong>&nbsp;Oases can provide water and sustenance during extended periods of drought, offering respite to both people and wildlife.</li>



<li><strong>Microclimates:</strong>&nbsp;The vegetation and water presence in oases can create slightly cooler and more humid conditions locally, mitigating the harshness of the desert climate.</li>



<li><strong>Adaptation strategies:</strong>&nbsp;Traditional oasis management practices may offer valuable lessons for adapting to water scarcity and climate change in wider regions.</li>
</ul>



<h2 class="wp-block-heading" id="h-oases-are-under-attack-on-multiple-fronts">Oases are under attack on multiple fronts </h2>



<ul>
<li><strong>Overexploitation of groundwater:</strong>&nbsp;As discussed, excessive pumping of groundwater for irrigation or other needs can deplete aquifers faster than they naturally recharge, endangering the long-term survival of the oasis.</li>



<li><strong>Climate change:</strong>&nbsp;Rising temperatures increase evaporation rates, making water scarcity even more severe. Changing rainfall patterns can disrupt the delicate water balance that sustains oases.</li>



<li><strong>Loss of glaciers:</strong>&nbsp;Glacier meltwater is a lifeline for many oases. As glaciers retreat due to climate change, this essential water source diminishes, threatening the oasis's future.</li>
</ul>



<p>“While higher temperatures increase glacier melt, temporarily boosting oases’ water supplies, as glaciers gradually disappear, the yield of meltwater will eventually decrease, leading to the shrinkage of oases once again,” Gui said.</p>



<h2 class="wp-block-heading" id="h-oases-and-desertification">Oases and desertification</h2>



<p>The delicate state of our oases demands a transformative approach. Here's what we can do:</p>



<ul>
<li><strong>Sustainable water management:</strong>&nbsp;Promote water conservation, efficient irrigation techniques, and find ways to replenish groundwater sources.</li>



<li><strong>Ecological land use:</strong>&nbsp;Halt destructive practices like overgrazing and support traditional land management that works in harmony with nature.</li>



<li><strong>International cooperation:</strong>&nbsp;Many rivers cross borders, and oases depend on them. Countries must work together to protect vital water resources.</li>
</ul>



<p>“Due to the unique mechanism of oasis formation, a river basin often nurtures multiple oases across several countries, making transboundary cooperation key to addressing water scarcity and promoting sustainable development,” Gui said.</p>



<p>Oases represent extraordinary resilience. In the face of harsh conditions, they offer life and beauty. Yet, their future hangs in the balance. By understanding the intricate dynamics shaping them and embracing sustainable practices, we have the power to safeguard these fragile wonders for generations to come.</p>



<p>The study is published in the journal <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023EF004086" target="_blank" rel="noreferrer noopener"><em>Earth's Future</em></a>.</p>



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Oases face severe threats from desertification

For centuries, desert travelers have relied on oases as life-giving...

<p>Despite its extreme conditions, featuring surface temperatures that can melt lead, volcanoes that spew lava, and thick clouds of sulfuric acid, Venus provides <a href="https://www.earth.com/news/venus-secret-past-may-have-implications-for-earths-future/" target="_blank" rel="noreferrer noopener">invaluable insights</a> into the search for life on other planets, according to a new study from <a href="https://www.ucr.edu/" target="_blank" rel="noreferrer noopener">UC Riverside</a>.</p>



<p>“We often assume that Earth is the model of <a href="https://www.earth.com/news/the-habitability-of-a-planet-is-affected-by-the-location-of-its-land/" target="_blank" rel="noreferrer noopener">habitability</a>, but if you consider this planet in isolation, we don’t know where the boundaries and limitations are,” said lead author Stephen Kane, a professor of planetary astrophysics at UCR. “Venus gives us that.”</p>



<h2 class="wp-block-heading" id="h-venus-as-a-reference-point-for-life">Venus as a reference point for life</h2>



<p>The experts gathered extensive data on both Earth and Venus, and positioned Venus as a crucial reference point for better understanding the conditions that might preclude life on other planets.</p>



<p>Despite having an atmosphere that would crush a human instantly, Venus shares many similarities with Earth, such as comparable mass and radius. Given their closeness, it raises the question of why Earth's fate was so different.</p>



<p>Many scientists believe the significant amount of solar energy Venus receives caused its atmosphere to become a runaway greenhouse - a hypothesis that Kane challenges. </p>



<p>“If you consider the solar energy received by Earth as 100%, Venus collects 191%. A lot of people think that’s why Venus turned out differently,” he said. “But hold on a second. Venus doesn’t have a <a href="https://www.earth.com/news/saturn-now-leads-the-solar-system-moon-race-with-145/" target="_blank" rel="noreferrer noopener">moon</a>, which is what gives Earth things like ocean tides and influenced the amount of water here.”</p>



<h2 class="wp-block-heading" id="h-more-missions-to-venus-are-needed">More missions to Venus are needed</h2>



<p>The paper also emphasizes the need for more missions to Venus to answer unresolved questions about its core size, rotation rate, magnetic field changes, and atmospheric chemistry.</p>



<p>“Venus doesn’t have a detectable <a href="https://www.earth.com/news/earths-magnetic-field-shifts-ten-times-faster-than-expected/" target="_blank" rel="noreferrer noopener">magnetic field</a>. That could be related to the size of its core,” Kane explained. “Core size also gives us information about how a planet cools itself. Earth has a mantle circulating heat from its core. We don’t know what’s happening inside Venus.”</p>



<p>Understanding the inner workings of Venus is vital because a planet’s interior dynamics greatly affect its atmosphere. This is evident on Earth, where the atmosphere is largely influenced by volcanic activity.</p>



<h2 class="wp-block-heading" id="h-upcoming-nasa-missions">Upcoming NASA missions</h2>



<p>NASA's upcoming missions, <a href="https://ssed.gsfc.nasa.gov/davinci/" target="_blank" rel="noreferrer noopener">DAVINCI</a> and <a href="https://science.nasa.gov/mission/veritas/">VERITAS</a>, will further explore these aspects. The DAVINCI mission will analyze the planet's thick atmosphere, and VERITAS will focus on the planet's surface without landing.</p>



<p>“DAVINCI will measure the atmosphere all the way from the top to the bottom. That will really help us build new climate models and predict these kinds of atmospheres elsewhere, including on Earth, as we keep increasing the amount of CO2,” Kane said.</p>



<p>According to the scientists, these missions will not only improve our understanding of Venus but also refine our assessments of <a href="https://www.earth.com/news/dinosaurs-are-helping-astronomers-in-the-search-for-extraterrestrial-life/" target="_blank" rel="noreferrer noopener">extraterrestrial life</a> possibilities.</p>



<h2 class="wp-block-heading" id="h-studying-venus-to-preserve-life">Studying Venus to preserve life</h2>



<p>“The sobering part of the search for life elsewhere in the universe is that we’re never going to have in situ data for an exoplanet. We aren’t going there, landing, or taking direct measurements of them,” Kane said. “If we think another planet has life on the surface, we might not ever know we’re wrong, and we’d be dreaming about a planet with life that doesn’t have it. We are only going to get that right by properly understanding the Earth-size planets we can visit, and Venus gives us that chance.”</p>



<p>“One of the main reasons to study Venus is because of our sacred duties as caretakers of this planet, to preserve its future. My hope is that through studying the processes that produced present-day Venus, especially if Venus had a more temperate past that’s now devastated, there are lessons there for us. It can happen to us. It’s a question of how and when,” Kane concluded.</p>



<h2 class="wp-block-heading" id="h-intriguing-facts-about-venus">Intriguing facts about Venus</h2>



<p>Venus, often dubbed Earth's "sister planet" due to its similar size and proximity, holds a variety of intriguing characteristics that set it apart in our solar system:</p>



<h3 class="wp-block-heading" id="h-extreme-atmosphere">Extreme atmosphere</h3>



<p>Venus has an incredibly thick atmosphere composed mostly of carbon dioxide, with clouds of sulfuric acid, making it inhospitable. This atmosphere creates a runaway greenhouse effect, leading to surface temperatures hot enough to melt lead - about 900 degrees Fahrenheit (475 degrees Celsius).</p>



<h3 class="wp-block-heading" id="h-crushing-pressure">Crushing pressure</h3>



<p>The surface pressure on Venus is about 92 times that of Earth, equivalent to the pressure found at about 3,000 feet (900 meters) underwater on Earth. This extreme pressure would crush most human-made objects.</p>



<h3 class="wp-block-heading" id="h-retrograde-rotation">Retrograde rotation</h3>



<p>Venus rotates on its axis in the opposite direction to most planets in the solar system, including Earth. This means the Sun rises in the west and sets in the east on Venus. Additionally, a day on Venus (one complete rotation on its axis) is longer than its year (one complete orbit around the Sun). It takes about 243 Earth days to rotate once, but only about 225 Earth days to complete an orbit.</p>



<h3 class="wp-block-heading" id="h-volcanic-landscape">Volcanic landscape</h3>



<p>Venus is covered with numerous <a href="https://www.earth.com/news/volcanoes-cover-nearly-the-entire-surface-of-venus/" target="_blank" rel="noreferrer noopener">volcanoes</a> and has a surface dominated by volcanic plains. It has more volcanoes than any other planet in the solar system, with over 1,600 major volcanoes, many of which are believed to still be active.</p>



<h3 class="wp-block-heading" id="h-lack-of-water-vapor">Lack of water vapor</h3>



<p>Despite being similar to Earth in size and composition, Venus has almost no water vapor in its atmosphere, and its surface is a dry, desert-like landscape. Any water that might have been present in the past likely evaporated due to the intense heat.</p>



<h3 class="wp-block-heading" id="h-brightest-planet">Brightest planet</h3>



<p>Venus is the brightest planet in our solar system and is often visible from Earth with the naked eye. It can appear as a bright star-like object in the morning or evening sky, which is why it's sometimes called the Morning Star or Evening Star.</p>



<h3 class="wp-block-heading" id="h-mysterious-wind-patterns">Mysterious wind patterns</h3>



<p>Despite the slow rotation on its axis, the atmosphere of Venus rotates much faster than the planet itself, a phenomenon known as super-rotation. Winds in the upper atmosphere can reach speeds up to 220 miles per hour (360 kilometers per hour).</p>



<p>These unique and extreme conditions make Venus an interesting subject of study to understand planetary processes and atmospheric dynamics in our solar system.</p>



<p>The study is published in the journal <a href="https://ui.adsabs.harvard.edu/link_gateway/2024arXiv240308830K/doi:10.48550/arXiv.2403.08830" target="_blank" rel="noreferrer noopener"><em>Nature Astronomy</em></a><em>.</em></p>



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How the ‘hellish’ planet Venus can help us find alien life

Despite its extreme conditions, featuring surface temperatures that can melt...

<p>Influenza is viewed by infectious disease specialists as the <a href="https://www.earth.com/news/time-traveling-pathogens-from-melting-permafrost-pose-great-risk-to-the-earth/" target="_blank" rel="noreferrer noopener">pathogen</a> with the highest pandemic potential, according to findings unveiled at a major global congress in Barcelona.</p>



<p>A survey conducted by the VACCELERATE Consortium revealed that 57% of the experts ranked influenza at the top of the list of pandemic threats. This highlights the persistent threat of influenza to global health.</p>



<h2 class="wp-block-heading" id="h-exploring-the-top-pandemic-threats">Exploring the top pandemic threats</h2>



<p>The survey reached out to a broad spectrum of experts from 57 countries, garnering 187 responses that provide a snapshot of the global perspective on infectious threats. </p>



<p>Influenza emerged as the primary pandemic concern due to its ability to mutate and spread widely each season. </p>



<p>Disease X - an undefined pathogen representing emerging diseases - and SARS-CoV-2, the virus behind the recent <a href="https://www.earth.com/news/low-iron-may-be-a-key-driver-of-long-covid/" target="_blank" rel="noreferrer noopener">COVID-19</a> pandemic, followed closely.</p>



<p>In their study, the experts evaluated a variety of pathogens, including those listed in the World Health Organization’s R&amp;D Blueprint for Action to Prevent Epidemics. </p>



<p>The blueprint serves as a proactive measure to identify and prioritize research on diseases that pose significant public health risks due to their infectivity, transmissibility, and potential for severe impact.</p>



<h2 class="wp-block-heading" id="h-prioritizing-pathogens-with-pandemic-potential">Prioritizing pathogens with pandemic potential</h2>



<p>Besides influenza, the survey highlighted other critical threats. Disease X, a placeholder for potential future pathogens, was ranked highest by 21% of respondents, underscoring the constant vigilance needed against unknown viruses.</p>



<p>Respondents also noted the significant impact of <a href="https://www.earth.com/news/shock-discovery-cats-play-a-role-in-spreading-covid-19/" target="_blank" rel="noreferrer noopener">SARS-CoV-2</a> and its predecessor, SARS-CoV, which caused the 2002-03 outbreak.</p>



<p>A smaller fraction of experts recognized lesser-known but equally concerning pathogens like the Crimean-Congo hemorrhagic fever virus and the Ebola virus, noting their deadly outbreaks.</p>



<p>Conversely, experts ranked viruses such as Hantavirus, Lassa virus, Nipah virus, henipavirus, and Rift Valley fever virus lower in terms of immediate pandemic potential, suggesting they pose a lesser immediate threat, yet emphasizing the ongoing need for monitoring and research.</p>



<h2 class="wp-block-heading" id="h-influenza-s-pandemic-threat">Influenza’s pandemic threat</h2>



<p>Dr. Jon Salmanton-García commented on the findings: “Each winter we have an influenza season. One could say that this means that every winter there are little pandemics. They are more or less controlled because the different strains are not virulent enough.” </p>



<p>“Yet, every season the strains involved change, that is the reason why we can get influenza several times in life and vaccines change year to year. In case a new strain becomes more virulent, this control could be lost.”</p>



<h2 class="wp-block-heading" id="h-insights-from-the-covid-19-pandemic">Insights from the COVID-19 pandemic</h2>



<p>The recent experiences with the COVID-19 pandemic have significantly shifted the landscape of pandemic preparedness.</p>



<p>Dr. Salmanton-García explained that the global response to COVID-19 has enhanced our approach to managing respiratory viruses, improving practices in social distancing, hand hygiene, mask usage, and vaccination strategies.</p>



<p>“In the COVID-19 pandemic, we have learned many things on how to approach a respiratory virus pandemic. This includes social distancing, hand cleaning, face masks, a renewed focus on vaccination, and trust in healthcare institutions. In parallel, institutions have also learned a lot. Preparedness and surveillance are now, vitally, better-funded,” said Dr. Salmanton-García.</p>



<h2 class="wp-block-heading" id="h-understanding-pandemic-threats">Understanding pandemic threats</h2>



<p>The study paints a clear picture of the infectious disease landscape, identifying influenza, Disease X, and coronaviruses among the top concerns for global health security. </p>



<p>The findings emphasize the need for continued vigilance, research, and preparation to mitigate the impact of potential future pandemics.</p>



<h2 class="wp-block-heading">More about pandemic threats</h2>



<p>Pandemic threats are often caused by novel <a href="https://www.earth.com/news/viruses-have-eyes-and-ears-on-their-hosts/" target="_blank" rel="noreferrer noopener">viruses</a> or bacteria to which the general population has little to no immunity. The severity and spread of these diseases can be influenced by various factors, including the pathogen's transmissibility, virulence, and the availability of effective treatments or vaccines.</p>



<p>Modern global connectivity through travel and trade, along with urbanization and environmental changes, can exacerbate the spread of <a href="https://www.earth.com/news/the-infectious-disease-landscape-is-changing-and-we-must-prepare/" target="_blank" rel="noreferrer noopener">infectious diseases</a>, making pandemics more likely.&nbsp;</p>



<p>The impact of a pandemic can be profound, not only causing widespread health crises but also affecting economies, social structures, and daily life. Governments and international organizations work to monitor and manage these risks through surveillance, preparedness plans, and public health interventions aimed at controlling the spread of diseases and minimizing their impact on society.&nbsp;</p>



<p>Effective response strategies often include measures such as vaccination campaigns, travel restrictions, quarantine, and public education about hygiene practices.</p>



<p>The research will be presented at the <a href="https://www.escmid.org/" target="_blank" rel="noreferrer noopener">European Society of Clinical Microbiology and Infectious Diseases</a>' (ESCMID) Global Congress in Barcelona later this month.</p>



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Influenza is considered the biggest pandemic threat

Influenza is viewed by infectious disease specialists as the pathogen...

<div class="vdb_player vdb_591c9e3c9efa894c3c6e150b58d96b98cd4fed198a0d2a49"><script type="text/javascript" src="//delivery.vidible.tv/jsonp/pid=591c9e3c9efa894c3c6e150b/vid=592d9a269cb28c266051113b/58d96b98cd4fed198a0d2a49.js"></script></div>
<p><span style="font-weight: 400;">The Sentinel-2A satellite shows us new footage from northeastern Iran, the second largest country in the Middle East.</span></p>
<p><span style="font-weight: 400;">Iran is in a dryland area classified as arid and semi-arid and characterized by rangeland, barren land and mountains.</span></p>
<p><span style="font-weight: 400;">At the center and the top left we can see alluvial fans, formed when streams or rivers hit plains and spread out. They represent the distinct pattern of water runoff from the mountains, where the eroded soil, with the help of rain, is carried from the mountain slopes to lower land.</span></p>
<p><span style="font-weight: 400;">At top left, resembling brush strokes in a painting, we can see the seasonal accumulation of water with various salt minerals evident as greys and whites.</span></p>
<p><span style="font-weight: 400;">Scattered throughout the image are many agricultural plots, distinct in such an arid and mountainous region featuring various rocky formations.</span></p>
<p><span style="font-weight: 400;">At the far right, the city of Bajestan is visible, with many agricultural fields around it. It is a city with a population of some 11,000. Saffron and pomegranate are its most important products, grown in the various plots on the left.</span></p>
<p><span style="font-weight: 400;">The shades of red indicate how sensitive the multispectral instrument on Sentinel-2A is to differences in chlorophyll content, providing key information on vegetation health.</span></p>
<p><span style="font-weight: 400;">Various towns or settlements are represented in grays throughout the image.</span></p>
<p><span style="font-weight: 400;">—</span></p>
<p><span style="font-weight: 400;">Credit: </span><a href="http://www.esa.int/" target="_blank"><span style="font-weight: 400;">European Space Agency</span></a></p>


A new look at northeastern Iran