Taxonomy term

geology

Survey says: U.S. lakes getting murkier

study of more than 1,000 lakes across the United States between 2007 and 2012 found that the number of murky green and brown lakes surpassed the number of clear blue lakes.

24 Dec 2018

Geologic Column: Light amid the darkness: Celebrations during the winter solstice

The winter solstice falls on Friday, Dec. 21, marking the arrival of winter and the shortest day of the year in the Northern Hemisphere. For at least 5,000 years, humans have celebrated this celestial event with festivals of light and ceremonies of renewal.
21 Dec 2018

"Critical Minerals" list snubs copper, sparks discussion of criticality

In 2017, the United States relied on imports for more than half the needed supply of 50 mineral commodities that are critical in manufacturing. Some of the commodities come from just a few major suppliers — especially China and Canada — or are produced in tiny quantities in just a few places. Others come from conflict zones. Some are produced only as byproducts of processing ores of major metals, such as copper and zinc. Such complex international supply chains are at risk of being disrupted by a variety of problems, from trade wars and market volatility to natural disasters and terrorism.

20 Dec 2018

Bubbly discovery may impact volcanic hazard assessment

Programs that manage volcanic hazards use a variety of tools and techniques to monitor impending eruptions. But researchers recently found evidence — in the form of gas bubbles bursting out of Hawaii’s Kilauea Volcano — suggesting that scientists should forgo one common method for assessing hazards from basaltic volcanoes: averaging gas composition measurements.

19 Dec 2018

Revealing the ghosts of glaciers past

On the ground, it’s hard to fathom the effects that glaciers once had on the now nearly ice-free Rocky Mountains, but from the air, the landscape is clearly haunted by the ghosts of glaciers past. In 2015, pilot and photographer Garrett Fisher set out in his antique 1949 Piper Cub aircraft to photograph all the remaining glaciers in the American Rockies. 
18 Dec 2018

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

Southern Ocean is absorbing less carbon

In the Southern Ocean surrounding Antarctica, complex and dynamic interactions among the atmosphere, cryosphere, and surface and deep ocean waters play an important role in climate. Although it covers only a quarter of Earth’s oceanic surface area, the Southern Ocean — with its cold temperatures and carbon-sucking algal blooms — has been estimated to take up 40 percent of anthropogenic carbon dioxide emissions. However, new data collected by a fleet of autonomous floating sensors show that the Southern Ocean is taking up significantly less carbon than scientists thought.

10 Dec 2018

Science by floats

The Southern Ocean Carbon and Climate Observations and Modeling project (SOCCOM) set out four years ago to study the Southern Ocean and its role and influence on global climate. The main mission of the project was to increase Southern Ocean observations, especially during the frigid winter months, to better understand climate change and biogeochemistry.

10 Dec 2018

Travels in Geology: Touring the Capital Geology of Washington, D.C.

This month, the American Geophysical Union will host its annual fall meeting in Washington, D.C. Take a tour of the city’s unexpected geology, showcased in both natural rock outcrops and the capital’s diverse suite of building stone found in museums and monuments on the National Mall.
07 Dec 2018

Comment: National Geological Surveys: The past, present and future

The oldest national geological survey (Britain’s) is 183 years old; the youngest (China’s) is 19. Yet all the surveys share commonalities. A symposium last June in Vancouver, British Columbia, examined where surveys have been and where they’re going.

06 Dec 2018

Pages