Taxonomy term

adityarup chakravorty

Did early agriculture knock the climate off track?

During the last 2.5 million years, Earth’s climate has seen cycles of advancing and retreating glaciers over much of the Northern Hemisphere. We are currently in a warm, interglacial period — one that’s been prolonged by increases in atmospheric concentrations of greenhouse gases, such as carbon dioxide and methane. According to a new study in Nature, these high concentrations of greenhouse gases have disrupted the recent pattern of cycling in Earth’s climate and pushed back the next ice age. The study also suggests that human activity, beginning thousands of years ago with early agriculture and continuing through to the present day, has fueled the rise in greenhouse gas concentrations.

12 Dec 2018

Monsoon strength affects global ice volumes, not vice versa?

In the 1920s, Serbian scientist Milutin Milankovitch proposed that cyclical changes in Earth’s orbital eccentricity, as well as its axial tilt and orientation, shape global climate. Part of his theory — widely accepted since — is that the amount of solar radiation, or insolation, reaching high northern latitudes is a major factor in regulating global ice volume and albedo, which in turn control the strength of tropical monsoons. But in a new study, researchers suggest that instead of global ice volume regulating monsoon strength, it’s mostly the other way around.

22 Oct 2018

Pluto's surprising dunes

Images and data sent back by NASA’s New Horizons spacecraft during its flyby mission to Pluto (and beyond) show a series of regularly spaced linear ridges sandwiched between a mountain range and Sputnik Planitia, a vast plain of nitrogen, carbon monoxide and methane ice. “When we first saw the New Horizons images, we thought instantly that these were dunes, but it was really surprising because we know there is not much of an atmosphere [on Pluto],” said Jani Radebaugh, a planetary scientist at Brigham Young University and co-author of a study in Science announcing the findings, in a statement.

10 Oct 2018

Searching for the volcanic origins of iron ore

Most iron ore comes from sedimentary deposits. However, a sizeable minority is mined from volcanic rocks, including those found along the Coastal Cordillera of northern Chile, and in Kiruna, Sweden.

09 Aug 2018

Cracking the temperature of columnar jointing

When molten rock cools and contracts, it sometimes cracks to form geometrically shaped columns. This process, called columnar jointing, has led to several famous geological structures.

20 Jul 2018

From silver to snow: Full cloud seeding cycle observed

Cloud seeding — adding particles to clouds to modify precipitation patterns — has been suggested as a way to trigger rain and snowfall, which could help sustain mountain snowpack and water supplies across the western U.S. However, it has been challenging to demonstrate the technique’s effectiveness and efficiency, in part because direct observations of the full chain of events involved in cloud seeding have been lacking.

25 May 2018

Measuring earthquakes using fiber-optic cables

Fiber-optic cables crisscross the world, ferrying digital data and enabling internet access and telecommunication. In a new study, published in Geophysical Research Letters, researchers tested whether fiber-optic cables can also be used to detect and measure earthquakes.

23 Mar 2018

Lakeshore shape influences lake-effect snow

On Dec. 11, 2013, Upstate New York’s Tug Hill region received more than 100 centimeters of snow in 24 hours. And annually, the region, which covers more than 5,000 square kilometers to the east of Lake Ontario, can see up to five times that amount. In comparison, Toronto, on the northwestern coast of the lake, averages less than 125 centimeters of snow each year.

06 Mar 2018

In the lab, machine learning improves quake forecasts

The U.S. Geological Survey estimates that about 500,000 detectable earthquakes occur worldwide every year. But accurate forecasts of when quakes will occur have long been out of reach, in large part because of the complexities of fault behavior.

29 Dec 2017

Microbes care about energy efficiency

Microbes live in some of the most extreme environments on Earth, from the crushing depths of deep-sea trenches to scalding geothermal springs. Part of the reason microbes thrive in many different environments is their ability to use a variety of energy sources — including light, organic matter, and inorganic materials like hydrogen, sulfur, and iron — to power the metabolic reactions that allow them to grow and survive.

20 Oct 2017

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