Taxonomy term

adityarup chakravorty

Small-scale factors influence mantle flow under the seafloor

In December 2011, scientists and technicians aboard the research vessel Marcus G. Langseth dropped several ocean-bottom seismometers into the deep Pacific more than 1,900 kilometers southeast of Hawaii to measure seismic activity and electrical conductivity to a depth of about 300 kilometers below the seafloor. Now, these measurements are providing new insights into how the mantle flows and deforms below the rigid tectonic plates that make up Earth’s surface.

22 Nov 2016

Bubble accumulation could explain massive volcanic sulfur releases

The spectacular 1815 eruption of Indonesia’s Mount Tambora spewed large amounts of sulfur gases into the atmosphere, which formed fine sulfur-rich particles that blocked sunlight and lowered global temperatures by more than half a degree Celsius, causing famine and death on a global scale.

23 Aug 2016

Mantle convection makes Earth's crust bob

From the earthquake-prone Himalayas and Andes to the volcanically active “Ring of Fire” around the Pacific, the boundaries of Earth’s tectonic plates are often sites of considerable geologic activity. In contrast, the interiors of tectonic plates have been thought to be relatively rigid and quiet.

18 Aug 2016

Searching for the ancestors of meandering rivers

It might be difficult to imagine Earth devoid of vegetation, but for billions of years the sun shone, winds blew and rivers flowed on a planet without any plants.

21 Jun 2016

Fossil leaves provide clues to ancient Australian habitat

Researchers have long thought that the scrublands of Australia developed over the last 25 million to 30 million years as part of a global trend toward colder and drier climates in which rainforests yielded ground to more open, fire-prone environments.

20 Apr 2016

Volcanic aerosols not enough to cause mass extinctions?

Mass extinctions — when more than half of Earth’s species disappear in a geologic instant — offer some of the planet’s most perplexing unsolved mysteries. Prolonged periods of volcanic activity have long been prime suspects for these ancient whodunits, the most recent of which finished off the last nonavian dinosaurs at the close of the Cretaceous about 66 million years ago. But scientists debate how drastic the environmental effects of such volcanism might have been, and whether other factors — like asteroid impacts, as in the end-Cretaceous extinction — played a big role as well.

25 Feb 2016

Beached iceberg alters Antarctic marine communities

Studying the effects of expanding sea ice around Antarctica has been challenging, however, as it is difficult to predict exactly where sea ice will expand and whether it will stick around long enough to make a difference on marine life. But a rare event involving an iceberg bigger than the island of Manhattan created just the environment that Graeme Clark, an ecologist at the University of New South Wales in Australia, and his colleagues needed to study how the sudden advent of long-term sea-ice cover affects marine communities.

21 Jul 2015

Megafloods mostly shaped Icelandic canyon landscape

A new study suggests that in one environment prone to catastrophic floods, the Jökulsárgljúfur Canyon in northeastern Iceland, the effects of several megafloods in the past 9,000 years have sculpted the canyon landscape far more so than “background” erosion caused by water and sediment flowing through it.

22 May 2015