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mary caperton morton

Ups and downs of potassium feldspar may play role in clouds and climate

For water vapor in the atmosphere to transform into icy, cloud-forming droplets, it needs a seed around which to condense, such as aerosols, sea salt or bacteria. One of the most effective seeds is mineral dust, in particular potassium feldspar, one of the main ingredients in granite. New research tracking fluxes of potassium feldspar in the atmosphere through geologic time is shedding light on the long-term importance of the mineral in cloud formation and climate feedback cycles.

30 May 2017

Timing of famed "Millennium Eruption" pinpointed

Changbaishan Volcano in northeastern China, on the border with North Korea (where it’s known as Mount Paektu), is steeped in superstition, having produced devastating eruptions several times in recorded history. Legends that a massive eruption in the 10th century led to the downfall of a regional empire have now been refuted, however, thanks to a new analysis of a fossilized tree killed by the eruption that dates the eruption to after the kingdom fell.

25 May 2017

Meteorites did not spark Ordovician biodiversification

During the Ordovician Period, roughly 470 million years ago, an asteroid the size of a small moon collided with another rocky object in the belt between Mars and Jupiter, shattering the asteroid into billions of pieces. Fragments from the epic collision still occasionally fall to Earth today, making up a large share of the meteorites recovered. But in the immediate wake of the Ordovician event, many pieces rained down on the planet, settling on the surface and in layers of rock forming at the time. In a new study, researchers studying some of these meteorite-rich layers have refined the timescale for the collision. The results bring into question a proposed link between the meteorite bombardment and an evolutionary uptick known as the Great Ordovician Biodiversification Event (GOBE).

23 May 2017

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

Are North Atlantic storm tracks shifting south?

As the Arctic warms, decreasing temperature differences between the Arctic and the lower latitudes may push North Atlantic storm systems south. The factors that influence storm tracks are complicated, however, and the accuracy of models predicting future storm tracks is uncertain. The results of a new study, in which researchers looked at changes in Atlantic storm tracks over the past 4,000 years, could improve the accuracy of predictive models and help Europe prepare for shifting storm patterns.

19 May 2017

How often should we expect volcanic ash clouds over Europe?

In 2010, an ash cloud from an eruption at Iceland’s Eyjafjallajökull Volcano led to the most disruptive shutdown of North Atlantic and European airspace in aviation history. Given the high level of activity of Iceland’s more than two dozen active volcanoes, how often are such events to be expected? A new study comparing volcanic ash records over the last 1,000 years suggests that fallout over Europe may be more common than previously anticipated.

17 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

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

Investigating erionite, asbestos' more carcinogenic cousin

Asbestos is notorious for causing lung cancer and other respiratory diseases, but it’s not the only type of fibrous mineral that affects human health. In the mid-1970s, erionite was linked to the unprecedented high mortality rate from mesothelioma in villages in central Turkey where volcanic tuff had been used as a building material for centuries. Like asbestos, erionite can occur as long thin fibers that, when inhaled, can persist in lung tissue for decades. New research looking at associations of iron with erionite is helping pathologists better understand why embedded erionite fibers sometimes lead to lung cancer.

08 May 2017

First trilobite eggs found in fool's gold

Trilobites were one of the most successful groups of animals to ever scurry across the seafloor, thriving for more than 270 million years. But how they reproduced has long been a mystery, since no fossil had ever been found with preserved eggs or genitalia. With the discovery of a cluster of trilobite eggs preserved in pyrite in upstate New York, however, scientists are getting the first glimpse of how these early arthropods reproduced.

01 May 2017

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