Today's Image of the Day 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.



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



"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."



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



"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.



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.



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;



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.



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.



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.



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



Image Credit: NASA Earth Observatory&nbsp;



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Sediment swirling in the Gulf of Alaska

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

Today's Image of the Day from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features an astronaut view of the Aladaghlar Mountains in northwestern Iran. These mountains are known for their strikingly colorful landscapes, which make them stand out among other mountain ranges.



"Ridges cast shadows in the valleys and other low elevation areas, creating a three-dimensional appearance. Human alterations to the landscape are most evident in riverbeds, where the even topography is easier to build on and navigate," said NASA.



"Natural processes over millions of years have folded rock layers of various compositions and colors into the curved patterns seen here. These folds are produced by tectonic forces operating along the convergent plate boundary of the Arabia and Eurasia plates. The convergence of these tectonic plates causes uplift, folding, and deformation of the colorful rock layers, and subsequent erosion exposes them."



One of the most remarkable features of the Aladaghlar Mountains is the vivid coloration of their slopes. The name "Aladaghlar" translates to "Colorful Mountains," which is a testament to their unique appearance. 



The Aladaghlar Mountains are part of a larger ecosystem that includes forests, meadows, and rivers, contributing to a rich biodiversity. The region supports a variety of wildlife, including several species that are unique to the area. The diverse wildlife add to the natural beauty and ecological importance of these <a href="https://www.earth.com/news/how-and-why-do-mountains-form-new-theories-for-an-age-old-mystery/">mountains</a>.



In addition to their natural appeal, the Aladaghlar Mountains hold cultural significance. The region has a rich history, with evidence of ancient civilizations and historical sites. Local communities have their unique cultures and traditions, which have been influenced by the natural environment of the mountains.



Image Credit: NASA Earth Observatory&nbsp;



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The Aladaghlar Mountains of northwestern Iran

Today's Image of the Day from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features a large sediment plume from the Yangtze River that extends hundreds of kilometers off the coast of China.



"Brown, sediment-laden water is visible along this shallow, turbid stretch of coast year-round, but a vast plume like the one visible here is a characteristic feature of winter. Scientists have proposed several causes of this seasonal phenomenon," said NASA.



"The ebb and flow of tides contain enough energy to stir up sediments from the seafloor, a 2017 study found. While there are also tides in the summer, the models used in the study showed that sediment only rises to the surface in the winter. That’s when temperatures and salinities at the sea surface and bottom are similar, allowing for vertical mixing to occur and for sediment to churn higher into the water column."



Additional studies have suggested that the summer monsoon’s influence on currents impedes the eastward flow of sediment out of the estuaries, noted NASA.



"Despite what looks like a glut of suspended sediment in the water, the overall amount of it flowing from the Yangtze River has declined steadily over the past several decades. The construction of dams, including the Three Gorges Dam, has been the primary driver of this trend."



It is important for scientists to track the movement of suspended sediment. This material can cause direct harm to marine life, as well as indirect harm by blocking sunlight.



The Yangtze River, also known as the Chang Jiang in Chinese, is the longest river in Asia and the third-longest in the world, following the Nile and the <a href="https://www.earth.com/news/amazon-river-dolphins-are-at-great-risk-of-extinction-due-to-human-activities/">Amazon</a>. It flows for over 6,300 kilometers (about 3,917 miles) from the glaciers of the Qinghai-Tibet Plateau in western China to the East China Sea at Shanghai.&nbsp;



The Yangtze River basin is a key region for China's agriculture, industry, and hydroelectric power production. The river's waters are used for irrigation, navigation, and as a source of freshwater. The basin is home to diverse wildlife, including the critically endangered Yangtze river dolphin or Baiji, which may now be extinct.



The image was captured on February 12, 2024 by the Visible Infrared Imaging Radiometer Suite sensor on the NOAA-20 satellite.



Image Credit: NASA Earth Observatory



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Sediment flows offshore from the Yangtze River 

Today's Image of the Day from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features the Ruki River in the Democratic Republic of the Congo (DRC). It is a tributary of the Congo River, one of the largest <a href="https://www.earth.com/news/warmer-rivers-keep-antimicrobial-resistant-genes-at-bay/">rivers</a> in the world by discharge and depth. 



The Ruki River, previously known as the Busira, merges with the Momboyo River near the town of Basankusu to become the Lulonga River, which eventually flows into the Congo River at the town of Lisala.



"If the appearance of the muddy Amazon River evokes a coffee cut with cream, the Ruki River, coursing gently through the Congo Basin, is like a dark tea," said NASA.



"On its slow path through mostly untouched lowland rainforest in the Democratic Republic of Congo (DRC), the water leaches organic material from vegetation, prompting some researchers to think it is one of the darkest blackwater rivers on Earth. The dissolved material in this distinctive water, scientists are finding, offers clues into the carbon cycle of tropical forests."



In a recent study, researchers measured the chemical composition and flow of the Ruki for the first time.&nbsp;



"The study reported that, as the water color suggests, the Ruki is rich in dissolved organic carbon compounds. It contains four times as much organic carbon as the Congo River and 1.5 times as much as the Rio Negro, the world’s largest blackwater river and a major tributary of the Amazon," said NASA.



Due to this heavy carbon load, the researchers concluded that “tropical forests like those around the Ruki might not accumulate quite as much carbon as we once thought.”



The region around the Ruki River is rich in biodiversity, hosting various species of flora and fauna. It is part of the Congo Basin, the second-largest tropical rainforest area in the world, which is a critical habitat for endangered species and a significant carbon sink.



The river is vital for the livelihoods of local communities. Fishing is a crucial activity, with many people depending on it for sustenance and income. The river also supports agriculture along its banks, where communities grow crops.



In many parts of the DRC, rivers like the Ruki are crucial transportation corridors due to the challenging and often nonexistent road infrastructure. The river enables the movement of people and goods, facilitating trade and access to markets, health care, and education.



The region faces several challenges, including deforestation, overfishing, and environmental degradation, which threaten its ecological balance and the livelihoods of people who depend on it. Efforts to manage and conserve the river's resources are vital for sustainable development.



Understanding and protecting the Ruki River and its surroundings are crucial for the DRC's environmental sustainability, economic development, and the well-being of its communities.



The image was captured by the OLI (Operational Land Imager) on Landsat 8.



Image Credit: NASA Earth Observatory&nbsp;



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The Ruki River in the Democratic Republic of the Congo

Today's Image of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> features dust streaming from Lago Colhué Huapi, a shallow endorheic lake located in the Chubut Province in southern Argentina.



"Strong northwesterly winds often race down the eastern side of the Andes Mountains and whip across the central Patagonian Desert. In the process, they sometimes lift dust from Argentina’s drying Lago Colhué Huapi, fueling intense dust storms," said NASA.



"Lago Colhué Huapi is a particularly rich source of dust because the shallow lake regularly grows and shrinks with variations in the flow of the Senguer River and the pace of evaporation. When lake water levels are low, as they were when MODIS captured this image, fine-grained, lightweight particles are easily transported by the wind."



<h2 class="wp-block-heading" id="h-dust-activity-from-lago-colhue-huapi">Dust activity from Lago Colhué Huapi</h2>



<a href="https://www.earth.com/news/dust-storms-in-the-gulf-of-alaska-help-shape-the-global-climate/">Dust storms</a> in this region are most common during the summer months from December to March. There are 15 to 30 dust storms in a typical year.&nbsp;



"Dust storms are frequent and persistent enough in this area that they have exposed an open-air archaeological site along the lake’s edge," said NASA.



"The Puesto Roberts 1 site, located in an old floodplain on the southeast side of Lago Colhué Huapi, was first identified in 2019 when archaeologists noticed that winds had exposed a five-centimeter layer of sandy loam soil littered with stone tools and the bones of a wild species of llama called guanaco."



"Archaeologists identified 427 artifacts at the site - including stone cutting blades, milling tools, scrapers, and egg-shaped bola stones used for hunting - spread across 15 square meters, according to a 2022 study led by Heidi Hammond, an archaeologist at the National University of the Patagonia San Juan Bosco."



<h2 class="wp-block-heading" id="h-more-about-lago-colhue-huapi">More about Lago Colhué Huapi</h2>



This lake is an interesting geographical feature primarily because it acts as a seasonal sink for the Senguerr River, which in turn gathers waters from various smaller streams in the region. 



<h3 class="wp-block-heading" id="h-size">Size</h3>



Due to its shallow nature, the size of Lago Colhué Huapi can vary significantly with the seasons and the amount of water it receives from its sources. During times of drought or reduced rainfall, the <a href="https://www.earth.com/news/climate-change-is-pushing-lakes-to-their-boiling-point/">lake</a> can shrink considerably, affecting the local ecosystem and the wildlife that depends on it.



<h3 class="wp-block-heading" id="h-climate">Climate</h3>



The lake's surroundings are characterized by a semi-arid climate, which influences the type of vegetation and animal life that can thrive in the area. Despite the harsh conditions, the region around Lago Colhué Huapi supports a variety of bird species, making it a site of interest for birdwatchers and naturalists.



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



In recent years, Lago Colhué Huapi has faced environmental challenges, including the impact of <a href="https://www.earth.com/news/alarming-study-most-of-the-worlds-largest-lakes-are-quickly-losing-water/">climate change</a>, which has led to lower water levels and increased salinity. These changes pose threats to the lake's ecological balance and the species that inhabit its waters and shores. The situation at Lago Colhué Huapi serves as a reminder of the broader environmental issues facing water bodies in arid and semi-arid regions around the world.



The image was captured on March 29, 2024 by the MODIS (Moderate Resolution Imaging Spectroradiometer) on NASA’s Aqua satellite.



Image Credit: NASA Earth Observatory



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Dust streams from Lago Colhué Huapi in Argentina 

Saguaros,In,Sonoran,Desert,After,Snow,Storm.

Global warming is undeniable, yet recent winters have witnessed record-breaking, extreme cold temperatures in unexpected areas. This paradoxical situation has scientists investigating the Warm Arctic-Cold Continent (WACC) phenomenon and its far-reaching impacts.



A study by the <a href="https://www.gist.ac.kr/en/main.html" target="_blank" rel="noreferrer noopener">Gwangju Institute of Science and Technology</a> underscores a significant change in WACC patterns from the 2030s onward, with implications for weather forecasting, climate modeling, and community preparedness.



<h2 class="wp-block-heading" id="h-warm-arctic-cold-continent-wacc-phenomenon">Warm Arctic-cold continent (WACC) phenomenon</h2>



The WACC phenomenon centers on how rapid <a href="https://www.earth.com/news/arctic-warming-could-speed-up-global-2c-temperature-rise-by-eight-years/" target="_blank" rel="noreferrer noopener">Arctic warming</a> and diminishing sea ice disrupt large-scale atmospheric circulation patterns, specifically the jet stream. 



The jet stream functions as a boundary separating cold Arctic air from warmer air to the south. A warming Arctic shrinks the temperature difference between the Arctic and the mid-latitudes, weakening the jet stream. 



This leads to a wavier jet stream that becomes prone to forming large, meandering loops. These loops allow frigid Arctic air to escape and plunge far southward into regions like North America, Europe, and Asia. 



Consequently, these areas experience intense cold snaps, demonstrating how a warming Arctic has far-reaching impacts on weather patterns well beyond the <a href="https://www.earth.com/news/the-arctic-may-be-ice-free-sooner-than-we-expected/" target="_blank" rel="noreferrer noopener">Arctic</a> region itself.



<h2 class="wp-block-heading" id="h-wacc-pattern-and-extreme-cold-events">WACC pattern and extreme cold events</h2>



The team behind this research at the Gwangju Institute dove into the science behind WACC.



"The WACC pattern has significantly influenced winter climates, but what we see currently is merely the start of a drastic shift," explained Professor Jin-Ho Yoon, lead researcher of the study. 



The WACC pattern is likely at its strongest in the 2020s.



"These events will sharply decline post-2030s. Yet, this decline does not mean reduced extreme weather events in the future. Instead, winters will get warmer as global warming intensifies. Although cold snaps will occur less frequently, they may have more severe consequences when they do happen," Professor Yoon warned.



<h2 class="wp-block-heading" id="h-altered-arctic-warming-and-wacc-pendulum">Altered Arctic warming and WACC pendulum</h2>



Imagine a pendulum swinging between a super-warm Arctic and freezing cold continents. This pendulum represents the WACC pattern. 



Right now, the <a href="https://www.earth.com/news/study-reveals-new-clues-about-rapid-arctic-warming/" target="_blank" rel="noreferrer noopener">Arctic</a> is warming rapidly, causing a large temperature difference between it and mid-latitude continents. 



This pushes the pendulum to swing wildly, resulting in the extreme cold snaps we see recently. Over the next few decades, the pendulum will start to slow down as the Arctic continues to warm and the temperature difference decreases. 



Eventually, the swings may become so small that we might not notice the WACC pattern as strongly. Even though the pendulum will slow down, it doesn't mean the end of <a href="https://www.earth.com/news/extreme-weather-dramatically-increases-the-threat-of-desert-locusts/" target="_blank" rel="noreferrer noopener">extreme weather</a>. 



Global warming means that overall, winters will become warmer. However, those occasional <a href="https://www.earth.com/news/extreme-weather-is-becoming-more-difficult-to-predict/" target="_blank" rel="noreferrer noopener">icy blasts</a> can still happen. Because they'll be less frequent than they are now, they'll be unexpected and out of the ordinary for places they hit. This makes them potentially even more severe in their impact when they do occur.



<h2 class="wp-block-heading" id="h-significance-of-studying-extreme-cold-events">Significance of studying extreme cold events</h2>



Scientists use complex computer models to predict the weather and how the climate might change. This research shows those models need updating to reflect the upcoming changes in WACC, otherwise, our predictions might be way off.



"Understanding the impact of the drastic shift in WACC events and devising adaptation and mitigation strategies determines the future of our winter climate," noted Ph.D. student Yungi Hong. 



<h2 class="wp-block-heading" id="h-vulnerable-communities">Vulnerable communities</h2>



Communities accustomed to experiencing frequent <a href="https://www.earth.com/news/arctic-warming-linked-to-extreme-winter-weather-in-the-u-s/" target="_blank" rel="noreferrer noopener">cold blasts</a> due to the WACC phenomenon are facing a new challenge. As global warming progresses, these cold events are predicted to occur less often. 



However, when they do happen, they are expected to be more intense and severe. This change means that the usual preparedness plans might no longer be sufficient. 



These communities will need to develop new strategies that are specifically designed to handle the increased severity of the cold events, even though they will happen less frequently. 



This involves enhancing infrastructure, improving emergency responses, and updating safety protocols to protect against the heightened risks of these less frequent, but more intense, cold blasts.



<h2 class="wp-block-heading" id="h-effects-of-extreme-cold-events-caused-by-wacc">Effects of extreme cold events caused by WACC</h2>



The WACC phenomenon is a complex climate pattern that describes how warming in the <a href="https://www.earth.com/news/tracking-arctic-climate-change-is-much-more-difficult-since-russia-invaded-ukraine/" target="_blank" rel="noreferrer noopener">Arctic</a> can lead to colder winters in parts of North America, Europe, and Asia. Here are the broader implications of WACC:



<h3 class="wp-block-heading" id="h-economic-effects-of-extreme-cold-events">Economic effects of extreme cold events</h3>



<ul>
<li>Agricultural disruption: Unpredictable weather patterns can threaten agricultural production, affecting crop yields and the timing of planting and harvesting. This can lead to economic losses for farmers and increased food prices.</li>
</ul>



<ul>
<li>Infrastructure stress: Infrastructure not designed to handle extreme cold may face operational challenges, requiring significant investments in upgrades or new technologies to ensure resilience.</li>
</ul>



<ul>
<li>Energy demand fluctuations: Extreme cold events can lead to spikes in energy demand as communities need more heating. This can strain energy supplies and increase costs.</li>
</ul>



<h3 class="wp-block-heading" id="h-social-impacts-of-extreme-cold-events">Social impacts of extreme cold events</h3>



<ul>
<li>Increased energy poverty: Higher energy demands can exacerbate energy poverty, where households are unable to afford adequate heating. This can lead to increased rates of illness and a lower quality of life.</li>
</ul>



<ul>
<li>Emergency services strain: More frequent and severe weather can overwhelm emergency services, from road maintenance to medical response during extreme weather events.</li>
</ul>



<h3 class="wp-block-heading" id="h-broader-climate-interactions">Broader climate interactions</h3>



<ul>
<li>Interactions with other phenomena: The effects of WACC can interact with other climatic phenomena like El Niño or La Niña, complicating predictions and impacts across different regions.</li>
</ul>



<ul>
<li>Feedback loops: Changes in sea ice and snow cover not only result from WACC but can also exacerbate warming and atmospheric changes, creating feedback loops that further destabilize climate patterns.</li>
</ul>



<h3 class="wp-block-heading" id="h-long-term-climate-predictions">Long-term climate predictions</h3>



<ul>
<li>Modeling challenges: Accurately modeling WACC impacts requires understanding these complex interactions and feedback mechanisms, which are currently challenging for climate models.</li>
</ul>



<ul>
<li>Future research needs: Continued research is essential to refine models and predictions, helping policymakers and communities better prepare for future conditions.</li>
</ul>



The WACC phenomenon is a stark reminder that climate change isn't simple. It brings a whole cascade of unpredictable effects. This research is a call to action: we need to work on reducing our impact on the planet and get ready for the unexpected ways in which our world will keep changing.



The study is published in <a href="https://www.nature.com/articles/s41612-024-00611-7" target="_blank" rel="noreferrer noopener">npj Climate and Atmospheric Science</a>.



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How extreme cold events fit into the global warming model

Global warming is undeniable, yet recent winters have witnessed record-breaking,...

A,Man,Standing,In,A,Cave,At,Sunset,Natural,Rock

The deserts of Saudi Arabia are home to a unique kind of treasure: caves and lava tubes. These <a href="https://www.earth.com/earthpedia-articles/7-surprising-facts-you-didnt-know-about-lava-tubes/" target="_blank" rel="noreferrer noopener">natural formations</a> were created by the intense heat from volcanic eruptions long ago. Today, these lava tubes offer insights into the lives of the early humans who managed to survive and thrive in this harsh landscape.



Conducted by <a href="https://www.griffith.edu.au" target="_blank" rel="noreferrer noopener">Griffith University</a>'s Australian Research Centre for Human Evolution (<a href="https://www.griffith.edu.au/australian-research-centre-human-evolution" target="_blank" rel="noreferrer noopener">ARCHE</a>), this remarkable research focuses on one such site, the Umm Jirsan cave. 



The study highlights new evidence of ancient human activities. It provides a deeper understanding of how people once lived in Saudi Arabia.



<h2 class="wp-block-heading" id="h-umm-jirsan-lava-tubes">Umm Jirsan lava tubes</h2>



Deep within the expansive Harrat Khaybar <a href="https://www.earth.com/wp-content/uploads/2024/04/Umm-Jirsan-Cave-system_credit-green-arabia-project_1m.jpg" target="_blank" rel="noreferrer noopener">lava field of Saudi Arabia</a> lies the archaeological treasure of lava tubes called Umm Jirsan. 



This sprawling underground lava tube serves as a natural shelter and a time capsule preserving millennia of Arabian prehistory. 



Led by Dr. Mathew Stewart, a team of archaeologists has discovered a wealth of artifacts at this site. The <a href="https://www.earth.com/news/inside-caves/" target="_blank" rel="noreferrer noopener">cave</a> has yielded numerous insights into the daily lives, cultural practices, and environmental adaptations of its ancient inhabitants.



"Our findings at Umm Jirsan provide a rare glimpse into the lives of ancient peoples in Arabia, revealing repeated phases of human occupation and shedding light on the pastoralist activities that once thrived in this landscape," said Dr. Stewart.



<h2 class="wp-block-heading" id="h-rock-art-in-saudi-arabia-s-lava-tube">Rock art in Saudi Arabia's lava tube</h2>



Archaeologists have managed to reconstruct a detailed account of how ancient travelers and inhabitants used this underground sanctuary. Among the fascinating discoveries within these ancient walls is an array of <a href="https://www.earth.com/news/stone-age-artists-carved-incredibly-detailed-animal-tracks-onto-rocks/" target="_blank" rel="noreferrer noopener">rock art</a>. 



The lava tube's surfaces are adorned with artistic depictions of cattle, sheep, goats, and even dogs. These images provide a window into the types of animals that were raised by these early peoples. They offer insights into the nascent days of animal domestication.



The rock art found within the Umm Jirsan lava tube serve as historical records, narrating the story of early domestication practices. Each scene offers insights into the animals that were raised and revered by these early communities.



Archaeologists have meticulously analyzed these drawings to construct a vibrant and detailed portrayal of life in and around Umm Jirsan. These illustrations reveal the daily survival strategies of <a href="https://www.earth.com/news/humans-arrived-in-the-americas-10000-years-earlier-than-previously-thought/" target="_blank" rel="noreferrer noopener">ancient humans</a>. 



Moreover, it also signified the cultural and social activities that flourished in this unique environment. Umm Jirsan was a key site for both practical survival and the development of early societal norms.



<h2 class="wp-block-heading" id="h-bones-offer-human-life-clues-in-saudi-arabia-s-lava-tubes">Bones offer human life clues in Saudi Arabia's lava tubes</h2>



The story doesn't end with the artwork. <a href="https://www.earth.com/news/how-ancient-humans-hunted-elephants-with-stone-tools/" target="_blank" rel="noreferrer noopener">Animal bones</a>, left behind after feasts of the past, give us even greater detail. Scientists analyzed these remains and made a fascinating discovery.



"Isotopic analysis of animal remains indicates that livestock primarily grazed on wild grasses and shrubs, while humans maintained a diet rich in protein,” explained Dr. Stewart. This tells us they were skilled herders, moving with the seasons to find grazing for their animals.



The detailed analysis of the rock art and other archaeological findings within the Umm Jirsan lava tube also reveals a significant shift in the human diet over time. It points to a major developmental milestone in the region: the rise of oasis agriculture. 



The rise in consumption of C3 plants, including various grasses and trees, hints at a shift toward a settled agricultural lifestyle. 



This dietary change suggests that ancient inhabitants started to cultivate and depend more on local plant sources. They strategically moved away from a lifestyle solely based on <a href="https://www.earth.com/news/our-hunter-gatherer-ancestors-did-much-more-gathering-than-hunting/" target="_blank" rel="noreferrer noopener">hunting and gathering</a>.



<h2 class="wp-block-heading" id="h-early-humans-demonstrated-environmental-adaptation">Early humans demonstrated environmental adaptation</h2>



This move towards agriculture is a critical indicator of the evolving human adaptation to the environment. It implies that the historically arid landscape of Arabia may have undergone periods of climatic change. The change made it more hospitable for settled life and enabling the growth of oasis agriculture. 



The emergence of this type of farming likely transformed the social structures of the time. These findings challenge the traditional view of ancient Arabia as an unchanging desert landscape. They highlight the dynamic nature of human adaptation to <a href="https://www.earth.com/news/ancient-humans-climate-change-2/" target="_blank" rel="noreferrer noopener">environmental changes</a>.



<h2 class="wp-block-heading" id="h-lava-tubes-and-early-humans-beyond-saudi-arabia">Lava tubes and early humans beyond Saudi Arabia</h2>



This isn't just about a single lava tube or the people who sheltered there. "This site likely served as a crucial waypoint along pastoral routes, linking key oases and facilitating cultural exchange and trade,” Dr. Stewart emphasized. 



Imagine Umm Jirsan as a prehistoric highway rest stop, a place where ideas, goods, and people from all over Arabia mingled.



"While underground localities are globally significant in archaeology and Quaternary science, our research represents the first comprehensive study of its kind in Saudi Arabia," said Professor Michael Petraglia, Director of ARCHE.&nbsp;



What happens in the lava tubes of Arabia helps us better understand the grand story of human resilience and adaptation all across the globe.



<h2 class="wp-block-heading" id="h-cultural-significance-of-saudi-arabia-s-lava-tubes">Cultural significance of Saudi Arabia's lava tubes</h2>



As discussed, the artifacts and rock art found in Saudi Arabia's lava tube serve as vibrant cultural expressions. These historical treasures shed light on the beliefs, values, and social structures of the people who created them.



The symbolism in the <a href="https://www.earth.com/news/massive-cave-bears-neanderthals/" target="_blank" rel="noreferrer noopener">cave</a>'s rock art is especially revealing. It shows a society that was deeply connected to its surrounding environment and the animals that inhabited it.



The scenes painted and carved onto the walls of Umm Jirsan include depictions of cattle, sheep, goats, and dogs, which were crucial to the livelihood and survival of these <a href="https://www.earth.com/news/stone-age-families-crawled-caves/" target="_blank" rel="noreferrer noopener">ancient communities</a>. 



These images suggest that pastoralism was not merely an economic activity but also held significant cultural importance. 



The prominence of these animals in the art could indicate their role in religious or ritual activities, suggesting a reverence for the life-sustaining resources these animals represented.



<h2 class="wp-block-heading" id="h-community-organization">Community organization</h2>



The variety of species depicted can tell us about the social stratification and community organization of the time. For instance, the ownership and breeding of larger herds might have been a sign of wealth and status. It could influence social hierarchies within the group. 



Additionally, the communal nature of pastoral life, as suggested by the art, implies a collaborative social structure where group cooperation was necessary for managing herds and sustaining the community.



The art also provides clues about the spiritual and existential views of the people. Animal figures could have been totemic symbols or part of mythological narratives, serving as protectors, symbols of fertility, or emblems of clan identities.



Such depictions allow archaeologists to infer not only the economic priorities of these ancient peoples but also their cosmological and spiritual landscapes.



<h2 class="wp-block-heading" id="h-redefining-ancient-knowledge">Redefining ancient knowledge</h2>



The discovery of such art in the secluded and enduring space of a lava tube highlights the importance of these locations not just as shelters but as cultural repositories.



Saudi Arabia is changing our understanding of the ancient world. It isn't all about Egypt or Mesopotamia – the desert has its own epic to tell. Umm Jirsan is just the beginning. 



"These findings underscore the immense potential for interdisciplinary investigations in caves and lava tubes, offering a unique window into Arabia's ancient past," Professor Petraglia explained.



The study is published in <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0299292" target="_blank" rel="noreferrer noopener">PLOS ONE</a>.



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Early humans lived in lava tubes in the scorching Arabian deserts

The deserts of Saudi Arabia are home to a unique...

A remarkable study led by researchers at the <a href="https://www.cam.ac.uk/" target="_blank" rel="noreferrer noopener">University of Cambridge</a> proposes a dramatic shift in our understanding of human evolution. The research suggests that interspecies <a href="https://www.earth.com/news/mammals-change-their-schedules-to-adapt-to-city-life/" target="_blank" rel="noreferrer noopener">competition</a>, rather than climate alone, significantly shaped the evolutionary trajectory of early humans.



Interspecies competition is a form of interaction where individuals of different species compete for the same resources in an ecosystem, such as food, space, or light. This type of competition can occur when resources are limited, leading to a struggle for survival among the competing species.



<h2 class="wp-block-heading" id="h-climate-vs-interspecies-competition">Climate vs. interspecies competition</h2>



Traditionally, researchers have viewed climate change as the primary driver of the emergence and extinction of <a href="https://www.earth.com/news/earliest-hominins-migrating/" target="_blank" rel="noreferrer noopener">hominin</a> species. This view is consistent with the patterns observed in most vertebrates. 



However, this new research indicates a crucial detail: for hominins - a group that includes <a href="https://www.earth.com/news/neanderthal-genes-still-influence-modern-humans/" target="_blank" rel="noreferrer noopener">modern humans</a> and our extinct relatives - competition between species was a crucial factor. This competition significantly influenced our evolutionary history.



<h2 class="wp-block-heading" id="h-minimal-interspecies-competition">Minimal interspecies competition</h2>



The study reveals that over five million years, competition was fundamental to "speciation," the emergence of new species in hominins.



"We have been ignoring the way competition between species has shaped our own evolutionary tree. The effect of climate on hominin species is only part of the story," explained Dr. Laura van Holstein, a biological anthropologist at <a href="https://www.clare.cam.ac.uk/" target="_blank" rel="noreferrer noopener">Clare College</a>.



Using Bayesian modeling and phylogenetic analyses, van Holstein and her team demonstrated a key finding. Like in other vertebrates, most hominin species emerged when interspecies competition for resources was minimal. 



This pattern, where speciation rates increase and then plateau before extinction rates rise, is consistent across many mammalian groups.



<h2 class="wp-block-heading" id="h-unique-evolutionary-trends">Unique evolutionary trends</h2>



However, the <a href="https://www.earth.com/news/baleen-whales-rewriting-the-evolutionary-history-of-the-largest-animals-ever/" target="_blank" rel="noreferrer noopener">evolutionary pattern</a> of our own genus, Homo, is strikingly different. "The more species of Homo there were, the higher the rate of speciation," noted Dr. van Holstein. 



"This suggests that competition between species actually resulted in the appearance of even more new species - a complete reversal of the trend seen in almost all other vertebrates."



This unique pattern of <a href="https://www.earth.com/news/human-evolution-may-be-the-biggest-roadblock-to-solving-climate-change/" target="_blank" rel="noreferrer noopener">evolution</a> in Homo is paralleled only by certain beetle species that inhabit islands. In these isolated ecosystems, unusual evolutionary trends can emerge.



"The patterns of evolution we see across species of Homo that led directly to modern humans is closer to those of island-dwelling beetles than other primates, or even any other mammal," said Dr. van Holstein.



<h2 class="wp-block-heading" id="h-fossil-records-and-beyond">Fossil records and beyond</h2>



Dr. van Holstein created a new database which tracked each time an example of a species was found and dated in the hominin fossil record - including around 385 occurences.



This comprehensive data allowed the researchers to reconsider the start and end dates for most known hominin species, totaling 17. 



Such an approach helps counteract the inherent limitations of fossil records. These records may not always capture the earliest or latest members of a species, due to geological and climatic factors affecting fossilization.



<h2 class="wp-block-heading" id="h-interspecies-competition-coexistence-and-adaptation">Interspecies competition, coexistence, and adaptation</h2>



Dr. van Holstein's findings suggest a new perspective. Some species previously thought to have evolved through "anagenesis" may have actually "budded." This indicates a branching off from an existing species rather than a linear evolution. 



This realization implies a greater level of coexistence among hominin species. It also indicates heightened interspecies competition - more than previously acknowledged. Additionally, the study underscores the role of technology in the evolution of the genus Homo.



For example, early hominins like Paranthropus evolved physiologically to adapt, developing features like robust teeth. In contrast, Homo species adopted tools, fire, and intensive hunting techniques.



These advancements enabled the latter species to rapidly exploit new ecological niches, bypassing the need for significant physiological changes.



<h2 class="wp-block-heading" id="h-a-legacy-of-interspecies-competition">A legacy of interspecies competition</h2>



Ultimately, these findings underscore the complexity of interspecies competition, human evolution and the unique evolutionary path taken by our ancestors. 



"These results show that, although it has been conventionally ignored, competition played an important role in human evolution overall," said Dr. van Holstein. "Perhaps most interestingly, in our own genus it played a role unlike that across any other vertebrate lineage known so far."



The study is published in the journal <a href="https://www.nature.com/articles/s41559-024-02390-z" target="_blank" rel="noreferrer noopener">Nature Ecology &amp; Evolution</a>.



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Human evolution was shaped by interspecies competition

A remarkable study led by researchers at the University of...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> describes why satellite images and measurements of our planet have become &#8220;essential to our survival, offering a new outlook of our world.&#8221;&nbsp;



Rising sea levels pose one of the biggest societal threats associated with climate change. According to ESA, satellite altimeter missions such as Copernicus Sentinel-6 are essential in monitoring global and regional changes in sea level.



&#8220;Unbeknown to many, the island of Crete, Greece, plays an important role in the Copernicus satellite altimetry constellation and on an international stage,&#8221; reports ESA.



&#8220;Satellite altimetry data have to be continuously monitored at the ESA’s Permanent Facility for Altimetry Calibration where different techniques have pioneered the use of transponders to provide the best measurements to validate satellite altimeters in space soon after launch.&#8221;



Dr. Craig Donlon explains that, by understanding planet Earth through satellite measurements, we are able to find evidence of change.&nbsp;



Video Credit: European Space Agency&nbsp;



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Satellites have become essential to our survival