Geotimes

Geotimes is the free electronic blog of the geosciences. Originally launched as GeoSpectrum, a newsletter of the American Geosciences Institute in 1995, Geotimes has been reborn as the go-to source of information on AGI's 51 Member Societies. The American Geosciences Institute coordinates and edits the blog, but it is the result of contributed materials from societies, geoscience organizations and others in the community.

To submit information to Geotimes, please contact Joe Lilek at geotimes@americangeosciences.org.

How the Arctic became salty

The Arctic Ocean hasn’t always been as salty as other oceans. In the Eocene, between 56 million and 34 million years ago, the water surrounding the North Pole — freshened by melt from sea ice and river runoff — was cut off from the Atlantic and Pacific oceans by land bridges. At some point, plate tectonic processes opened the North Atlantic, submerging the land bridges and allowing saltwater to pour into the Arctic, but the timing and details of these events are largely unknown. New research suggests a tipping point may have been reached as one particular land bridge submerged far enough below the ocean surface.
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Benchmarks: September 23, 1806: Lewis and Clark's Corps of Discovery returns from the West

It’s been called the greatest camping trip of all time. Statues, counties, waterways, mountains, military vessels, and even two colleges bear the names of the journey’s leaders. Their journals are among our greatest national treasures, and their adventures have inspired generations of explorers. Two hundred and eleven years ago this month, Captains Meriwether Lewis and William Clark and their 31-man Corps of Discovery returned to St. Louis, the frontier town where they had started their journey 28 months and nearly 13,000 kilometers of wilderness earlier on May 14, 1804.
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Less-developed countries with high climate risk need better access to weather and climate data

Rising seas, more persistent droughts and more frequent severe weather events are predicted to occur in the coming decades as the planet continues warming. In a new study, researchers who analyzed spending internationally on weather and climate information services (WCIS) suggest that access to reliable WCIS is becoming more vital for communities and governments looking to assess their vulnerability and to safeguard people and property amid changing climates.
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Less-developed countries with high climate risk need access to better weather and climate data

Rising seas, more persistent droughts and more frequent severe weather events are predicted to occur in the coming decades as the planet continues warming. In a new study, researchers who analyzed spending internationally on weather and climate information services (WCIS) suggest that access to reliable WCIS is becoming more vital for communities and governments looking to assess their vulnerability and to safeguard people and property amid changing climates.
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Down to Earth With: Paleobiologist Gregory Erickson

As an undergraduate at the University of Washington, Gregory Erickson wasn’t sure what he wanted to do. He started out as an engineering major, then dabbled with getting a degree in wildlife management. In 1986, having taken numerous science courses, he happened to compare notes with his best friend, a geology major, and realized he was just a few courses shy of obtaining a geology degree himself. Eager to finish college, Erickson signed up for a class in vertebrate paleontology focusing on dinosaurs — a decision that ultimately changed his life.
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Volcanism triggered end-Triassic extinction

The end-Triassic mass extinction exterminated up to three-quarters of all species on land and in the oceans 201 million years ago. This die-off opened up ecological niches and allowed for, among other changes, dinosaurs to diversify and spread across terrestrial ecosystems during the rest of the Mesozoic. Volcanism has long been implicated in the extinction, but whether it had a major impact on the planet at the time has remained unclear. In new research, scientists observed elevated mercury concentrations in extinction-aged rocks from around the world. Because volcanism is the main nonanthropogenic source of mercury in the environment, the findings suggest that volcanic activity was likely the main extinction trigger at the end of the Triassic.
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Jerusalem tower facelift reveals it's 1,000 years younger

Jerusalem is one of the oldest cities in the world, dating back to at least 2400 B.C. Downhill from the heart of the city is Gihon Spring, a year-round natural fount that was likely the primary water source for the ancient city. Defensive fortifications built around the spring, known as the Spring Tower, were originally dated to the Middle Bronze Age, around 1700 B.C., but a new study reveals the tower could be as much as 1,000 years younger.
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