Taxonomy term

july 2015

Brachiopod die-off signaled mid-Permian mass extinction

Since the explosion of complex lifeforms before the turn of the Cambrian, the expansion of life on Earth has been punctuated by a quintet of global mass extinctions known as the “Big Five.” The biggest of these happened toward the end of the Permian Period about 252 million years ago, when 95 percent of all species went extinct. In a new study, scientists have proposed that a sixth global extinction, about 10 million years before the End-Permian die-off, should be added to the list.

16 Jul 2015

Red Planet Roundup: July 2015

With two rovers patrolling the surface of Mars, five spacecraft in orbit above it, and scientists here on Earth studying the Red Planet from afar, new findings are announced often. Here are a few of the latest updates.
 
15 Jul 2015

Bare Earth Elements: "Volcano of Fire" eruption forces evacuations in Mexico

Mexico’s civil protection agency, along with local officials, issued an emergency declaration Saturday for the area surrounding Colima Volcano, after the eruption that began on Thursday intensified into the weekend. The eruption is said to have sent towering clouds of ash upwards of 4 kilometers into the sky, while lava and pyroclastic flows have spewed down the flanks of the volcano also known as Volcán de Fuego, or Volcano of Fire — one of Mexico’s most active.

13 Jul 2015

Wind whips canyons into shape

As a force of nature, wind is usually afforded less respect than water. Sure, it can topple trees and, in extreme cases, peel roofs off houses. But it can’t carve mighty canyons like water can — or can it? A new study suggests that geologists may have underestimated wind’s role in shaping valleys in arid environments, both on Earth and on Mars.
 
13 Jul 2015

Deforestation hangs climate out to dry

Across the tropics, vast swaths of forest have been cleared to make room for crops and livestock. Beyond releasing vast stores of carbon trapped in soil and biomass, tropical deforestation has the potential to alter hydrological cycles in ways that could affect temperature and precipitation patterns around the planet, according to a new report in Nature Climate Change.
 
13 Jul 2015

Did crustal chemistry buoy Western Plains?

The mighty mountains of the American West may captivate artists and adventurers with their rugged allure, but it’s the humble High Plains that intrigue certain geologists. For decades, scientists have puzzled over the origins of this vast plateau, which stretches for more than 500 kilometers east of the Rockies.
 
12 Jul 2015

Laser experiments illuminate landslide physics

How does cereal pour from the box? Why do grains of wheat become wedged inside a hopper? What happens to soil when a slope collapses in a landslide? And, more broadly, what do these diverse phenomena have to do with each other?
 
11 Jul 2015

Aquifers contaminated by Supertyphoon Haiyan storm surge

Supertyphoon Haiyan, which battered the Philippines in November 2013, was the most powerful hurricane to make landfall ever recorded. A new study has quantified damage done by the resulting storm surge to the fragile coastal aquifers that residents of one town rely on, and how long it might take for the aquifers to recover.

09 Jul 2015

Soil may supply surging streams after earthquakes

Earthquakes don’t just rattle buildings and psyches — they shake up the hydrological cycle too. Scientists have long noticed spikes in streamflow following big quakes, but they have yet to pinpoint the causes of these surges. While most proposed explanations conjure different ways of uncorking groundwater reservoirs, a new study suggests that at least some of this extra water may actually get shaken out of the soil.
 
09 Jul 2015

Great drying led to great dying down under

If not for the megafaunal extinctions that wiped out many large animals at the end of the Pleistocene, the world might be a very different place today — with humans coexisting alongside still-living saber-toothed tigers, woolly mammoths and 3-meter-tall birds. The agents of these mass extinctions have been debated for decades: Were shifting climates, or our spear-wielding ancestors mainly responsible? A new study of the receding shorelines of Australia’s largest lake has found that a substantial drying of the environment, more so than human pressure, is mostly to blame for the loss of megafauna down under.
 
08 Jul 2015

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