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geology

Geologic Column: Proposing a new U.S. Holiday: Explorers' Day

October has two holidays that celebrate two individuals both heralded as the discoverers of the New World: Christopher Columbus and Leif Erikson. Perhaps it’s time for something new.

14 Oct 2016

Comment: Did life start on a snowball?

Somewhere toward the end of the Hadean, life emerged on Earth. Conventional wisdom suggests the Hadean was a hothouse, but what if instead it were a global icehouse? Could life still have emerged?

06 Oct 2016

Water use soared as workers flocked to North Dakota's oilfields

Amid North Dakota’s oil boom, about 24,000 temporary oilfield workers moved to Williams County — in the state’s Bakken oil shale region — between 2010 and 2012, almost doubling the area’s population. In a new study, researchers found that those workers have been responsible for the region’s skyrocketing water use almost as much as hydraulic fracturing by the oil industry itself.

 
06 Oct 2016

Ancient landslide gave us Zion Canyon

It took about 20 seconds for the Sentinel rock landslide to tumble into Zion Canyon, but those seconds changed the landscape for thousands of years.

 
03 Oct 2016

Benchmarks: October 2, 1574: Dutch unleash the ocean as a weapon of war

In 1574, the city of Leiden in the Netherlands was brought to its knees: By August of that year, about 6,000 of the city’s roughly 15,000 inhabitants had either starved to death, been killed by the Black Plague or had succumbed to dysentery. Plague doctors in their crow-beaked masks roamed the streets amid famished and diseased citizens drinking foul water from canals. No one knew when, if ever, help would come, for beyond Leiden’s walls the Spanish army was laying siege and cutting off all supply routes into the city.

02 Oct 2016

Clouds can form without particles

In addition to their aesthetic and photogenic appeal, clouds play a crucial role in Earth’s climate and ecosystems, helping regulate temperatures by reflecting sunlight. All clouds — from fluffy cumulus to wispy cirrus — grow from seeds that, more often than not, are tiny particles of pollen, dust or chemical aerosols that float into the atmosphere from Earth’s surface. Sulfuric acid, a byproduct of volcanic eruptions and fossil fuel combustion, is one of the most ubiquitous precursors to atmospheric aerosols today and has long been thought to play a major role in modern cloud formation. But what about earlier in Earth’s history, before humans impacted the atmosphere as much? Three new studies, representing both experimental and field data, suggest that the planet’s plants and trees might have done just fine on their own pumping cloud-forming aerosols into the skies.

30 Sep 2016

Tectonic rejuvenation in North America's ancient mountains

The mountains of eastern North America, like the Appalachians, Adirondacks and White Mountains, are old: They grew as the pieces of the supercontinent Pangea collided and assembled more than 300 million years ago. It’s been long thought that, after forming — and subsequently undergoing additional uplift and deformation due to rifting during the opening of the Atlantic Ocean — the mountains fell dormant between about 160 million and 200 million years ago. But new work is adding to a growing body of evidence suggesting the ranges were tectonically active well after that.

29 Sep 2016

Travels in Geology: Guatemala's Volcan Pacaya: A feast for the senses

Guatemala is home to 22 volcanoes, several of which visitors can climb. The most popular is the active Volcán Pacaya; the hike is relatively easy, the views spectacular, and visitors can roast marshmallows near the summit. 

28 Sep 2016

California drought stops slow-moving landslides

Most people think of landslides as fast-moving events, but many slides creep slowly, advancing over hundreds or thousands of years. In a new study, researchers looking at creeping landslides in California have revealed an unexpected consequence of the state’s ongoing drought: Many of the slides have nearly stopped due to the lack of water in the soil.

27 Sep 2016

Bad weather hampered Mongol invasion of Europe

In 1241, the armies of the Mongol Empire, continuing their campaign through Asia and Europe, invaded western Hungary. Before long, however, the Mongols withdrew their forces, beating a sudden retreat that has long baffled historians. Now, drawing on high-resolution climate data from tree rings, researchers may have found a clue as to why: It seems wet weather created adverse conditions for the Mongol army, eventually forcing it to retreat from what was to become historically its westernmost advance.

 
25 Sep 2016

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