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13 May 2019
La Niña’s effect on droughts can be traced back to U.S. Civil War
The Civil War drought – one of the worst to afflict the U.S. in centuries – occurred in the mid-1850s to the mid-1860s. That drought is infamous for its effects in the U.S. Southwest and parts of the Great Plains, where it led to the near extinction of the American bison and played an important role in changing the course of the Civil War by causing food and water shortages, slowing the advance of part of the Confederate army in 1862.
8 February 2017
Greenland Ice Sheet melting can cool subtropics and alter climate
A new study finds evidence that the last time Earth was as warm as it is today, cold freshwater from a melting Greenland Ice Sheet circulated in the Atlantic Ocean as far south as Bermuda, elevating sea levels and altering the ocean’s climate and ecosystems.
13 January 2016
Ocean circulation changes may have killed cold-water corals
Successive and abrupt changes in North Atlantic ocean circulation over the past 4,500 years seem to have caused major reductions in some cold-water coral ecosystems, finds a study published in Geophysical Research Letters, a journal of the American Geophysical Union.
The new study shows changes in sea surface circulation over the last few thousand years were more sudden than previously thought and in some cases led to abrupt collapses of cold-water coral ecosystems. The researchers found the first evidence that perturbations in the Atlantic Meridional Overturning Circulation (AMOC) led to cold-water coral ecosystems decline from 100 to 1,200 years ago.
1 December 2015
Seismic risk in eastern Mediterranean higher than previously estimated
The eastern Mediterranean is more seismically active than previously assumed, a new study finds. On a geological time scale, seismic activity around the island of Crete has generated large earthquakes in bursts, potentially increasing the future risk for earthquakes and tsunamis in the region.
20 October 2015
Formation of coastal sea ice in North Pacific drives ocean circulation and climate
An unprecedented analysis of North Pacific ocean circulation over the past 1.2 million years has found that sea ice formation in coastal regions is a key driver of deep ocean circulation, influencing climate on regional and global scales.
3 June 2014
Modern ocean acidification is outpacing ancient upheaval, study suggests
Some 56 million years ago, a massive pulse of carbon dioxide into the atmosphere sent global temperatures soaring. In the oceans, carbonate sediments dissolved, some organisms went extinct and others evolved.
Scientists have long suspected that ocean acidification caused the crisis—similar to today, as manmade carbon dioxide combines with seawater to change its chemistry. Now, for the first time, scientists have quantified the extent of surface acidification from those ancient days, and the news is not good: the oceans are on track to acidify at least as much as they did then, only at a much faster rate.
GeoSpace is a blog on Earth and space science, managed by AGU’s Public Information staff. The blog features posts by AGU writers and guest contributors on all sorts of relevant science topics, but with a focus on new research and geo and space sciences-related stories that are currently in the news.