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Categories: Geoscience: Geomagnetic Storms, Paleontology: Climate

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Around 250 million years ago, 700 species of reptiles closely related to the modern-day crocodile roamed the earth, now new research reveals how a complex interplay between climate change, species competition and habitat can help explain why just 23 species of crocodile survive today.     

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Societies and political structures, like the humans they serve, appear to become more fragile as they age, according to an analysis of hundreds of pre-modern societies. A new study, which holds implications for the modern world, provides the first quantitative support for the theory that the resilience of political states decreases over time. 

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An international multidisciplinary team consisting of solar physicists, geophysicists, and historians from nine countries analysed observations of an extreme solar-terrestrial storm reported in historical records from February 1872. Their findings confirm that a moderate sunspot group triggered one of the largest magnetic storms ever recorded, almost covering the entire night sky with colourful aurorae in both hemispheres. If such an extreme storm occurred today, it would severely disrupt modern technological infrastructure. Their study emphasizes the importance of looking at historical records in light of modern scientific knowledge.

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Identifying how and why Antarctica's major ice sheets behaved the way they did in the early Miocene could help inform understanding of the sheets' behavior under a warming climate. Together, the ice sheets lock a volume of water equivalent to more than 50 meters of sea level rise and influence ocean currents that affect marine food webs and regional climates. Their fate has profound consequences for life nearly everywhere on Earth.  

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A recent study demonstrates how dripstones can be crucial for reconstructing past climates. The new approach can provide a detailed picture of the climate around early human occupations in South Africa.

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The San Joaquin Valley in California has experienced vast variability in climate extremes, with droughts and floods that were more severe and lasted longer than what has been seen in the modern record, according to a new study of 600 years of tree rings from the valley.

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A landmark study into the geological timescale distribution of sediment and nutrients over 500 million years shows that species biodiversity on Earth is driven by landscape dynamics.

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Researchers have discovered a new relationship between the Sun's magnetic field and its sunspot cycle, that can help predict when the peak in solar activity will occur. Their work indicates that the maximum intensity of solar cycle 25, the ongoing sunspot cycle, is imminent and likely to occur within a year.

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Scientists have made a surprising discovery that sheds new light on the role that oceanic deoxygenation (anoxia) played in one of the most devastating extinction events in Earth's history. Their finding has implications for current day ecosystems -- and serves as a warning that marine environments are likely more fragile than apparent. New research, published today in leading international journal Nature Geosciences, suggests that oceanic anoxia played an important role in ecosystem disruption and extinctions in marine environments during the Triassic--Jurassic mass extinction, a major extinction event that occurred around 200 million years ago.  Surprisingly however, the study shows that the global extent of euxinia (an extreme form of de-oxygenated conditions) was similar to the present day.

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Using historical records from around Australia, an international team of researchers have put forward the most accurate prediction to date of past Antarctic ice sheet melt, providing a more realistic forecast of future sea level rise.   The Antarctic ice sheet is the largest block of ice on earth, containing over 30 million cubic kilometers of water.   Hence, its melting could have a devasting impact on future sea levels. To find out just how big that impact might be, the research team turned to the past.  

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Ancient cycad lineages that survived the extinction of the dinosaurs may have done so by relying on symbiotic bacteria in their roots to fix atmospheric nitrogen. The finding came from an effort to understand ancient atmospheres, but became an insight into plant evolution instead.

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Past cold periods such as the Little Ice Age were associated with reduced strength of North Atlantic currents and increased surface salinity in the Caribbean. This was accompanied by disturbances in the distribution of salt to the north leading to longer, stronger cooling phases in the northern hemisphere.

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During the last ice age, the last glacial maximum about 20,000 years ago, the climate in the North Atlantic underwent much greater multi-centennial variability than it does in the present warm period. This is supported by evidence found in ice and seafloor cores. Researchers have now shown, based on a climate model, that internal mechanisms such as temperature and salinity distribution in the ocean are driving this multi-centennial variability.

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A new study takes an important step toward reconstructing a global history of water over the past 2,000 years. Using geologic and biologic evidence preserved in natural archives -- including 759 different paleoclimate records from globally distributed corals, trees, ice, cave formations and sediments -- the researchers showed that the global water cycle has changed during periods of higher and lower temperatures in the recent past.

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Researchers have mapped how land use changed across Britain throughout the last century. The new map reveals how and where some 50 per cent of semi-natural grassland was lost, including 90 per cent of the country's lowland meadows and pasture, as the nation intensified its agriculture.

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Large geomagnetic storms disrupt radio signals and GPS. Now, researchers have identified the previous underestimated role of the ionosphere, a region of Earth's upper atmosphere that contains a high concentration of ions and free electrons, in determining how such storms develop. Understanding the interactions that cause large geomagnetic storms is important because they can disrupt radio signals and GPS. Their findings may help predict storms with the greatest potential consequences.

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A new Antarctic ice sheet modeling study suggests that meltwater flowing out to sea from beneath Antarctic glaciers is making them lose ice faster.   

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The explosion of the underwater volcano Kolumbo in the Aegean Sea in 1650 triggered a destructive tsunami that was described by historical eye witnesses. A group of researchers has now surveyed Kolumbo's underwater crater with modern imaging technology and reconstructed the historical events. They found that the eyewitness accounts of the natural disaster can only be described by a combination of a landslide followed by an explosive eruption.

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Human populations in Neolithic Europe fluctuated with changing climates, according to a new study.

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Scientists analyzed open-source data to track vegetation changes across North America since the end of the Pleistocene Epoch, and conclude that humans have had as much of an impact on the landscape as the retreat of the glaciers at the end of the Ice Age.