GEOLOGY

geology

When and how did plate tectonics begin on Earth?

Earth’s surface is a shifting puzzle of plates that collide and diverge, generating earthquakes, fueling volcanoes, opening ocean basins and raising mountain ranges. But when and how did this process — unique in our solar system as far as we know — begin? 
22 May 2017

"Blob"-related warming contributed to Pacific Northwest ozone spike

In June 2015, instruments on Oregon’s Mount Bachelor recorded mean ozone for the month at 56 parts per billion, more than 20 percent higher than the average level for the 11 years prior. Other stations around the West noted similarly high readings, puzzling scientists over the cause of the rise. In a new study in Geophysical Research Letters, researchers describe a confluence of meteorological conditions that appear to have driven the phenomenon.

18 May 2017

Tibetan Plateau populated long before advent of agriculture

Due to the harsh living conditions of the Tibetan Plateau — which has an average elevation over 4,500 meters — archaeologists have long assumed that people didn’t live in the Himalayan high country until after the adoption of agriculture in this region of the world, about 3,600 years ago. But a new study of a trove of handprints and footprints found around a fossilized mud spring in Tibet is suggesting that people may have lived here as early as 13,000 years ago.

16 May 2017

Geomedia: Film: 'Written on Water': A Modern Tale of a Dry West

An endless patchwork of circular fields surrounds the small West Texas town of Olton. The unnatural shapes and sharp boundaries of the brown and green fields result from center-pivot irrigation systems that pull water from the Ogallala Aquifer and allow more crops to grow than the semi-arid landscape would otherwise allow. On these dusty farms and within town offices a drama is unfolding over what to do as irrigation wells run dry.

11 May 2017

Sea-surface temperatures during last interglacial similar to modern day

During the last interglacial period, between 129,000 and 116,000 years ago, global sea levels were 6 to 9 meters higher than at present. Scientists have long wondered how global atmospheric and ocean temperatures then compared to modern times, but efforts to reconstruct such temperatures have often fallen short. In a new study, researchers who compiled past records of sea-surface temperatures (SSTs) have revealed that SSTs during the last interglacial were similar to modern day temperatures. But, the similarity doesn’t necessarily predict a future surge in sea levels.

10 May 2017

Travels in Geology: Geo-diversity and geologic history in the North West Highlands of Scotland

The complex rocks of the North West Highlands of Scotland —which span two-thirds of Earth’s history — include the oldest rocks in the United Kingdom, as well as some young, glacially sculpted landscapes. They also hold a prominent place in the history of geology.
09 May 2017

Fossil forest recorded ancient sunspots

The sun’s surface is home to dark, relatively cool blotches of high magnetic activity known as sunspots, which vary in number over a roughly 11-year cycle. In a new study in Geology, scientists found evidence of this solar cycle dating back 290 million years to the Permian Period.

05 May 2017

Did Jurassic tectonics lead to supergiant oilfields?

More than 6 percent of global oil production comes from a single oilfield: the supergiant Ghawar oilfield in eastern Saudi Arabia, which produces more than 5 million barrels of crude oil every day. In a new study in GSA Today exploring the origins of this vast oilfield, researchers have found that extensive tectonic plate movements during the Middle and Late Jurassic may have created the conditions necessary for the formation of the Ghawar and several other oilfields across the Middle East.

01 May 2017

And then there was one: Ceres' disappearing ice volcanoes

Earth has numerous volcanoes, both active and extinct — some of which continue to tower over landscapes long after they finished erupting. On the chilly dwarf planet Ceres, however, scientists have identified just a single volcano — an ice-erupting cryovolcano — raising questions about whether others ever existed there and, if so, what happened to them. In a new study, researchers suggest that Ceres has likely had other volcanoes, but that, over time, their icy slopes have been flattened beyond recognition.

28 Apr 2017

Grapes reveal impacts of sulfur-rich Samalas eruption on 13th-century climate

The A.D. 1257 eruption of the Indonesian volcano Samalas sent an ash plume an estimated 43 kilometers into the sky in one of the most sulfur-rich eruptions of the last 7,000 years. A new study using tree rings, ice cores and historical records investigates how this colossal eruption impacted climate across the Northern Hemisphere, finding that the eruption triggered severe cold in some regions, while other areas were less affected. The pattern could be explained by the behavior of sulfate particles in the atmosphere, researchers suggest.

28 Apr 2017

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