Taxonomy term

Features

Carbon and the city: Tracking emissions from megacities

Sometime in the first century A.D., Rome’s population passed 1 million. It took more than 18 centuries for a city to surpass the 10 million mark, which both New York City and Tokyo did by 1950. Just six decades later, the world now has about 20 such “megacities” with populations of 10 million or more, including the largest, Tokyo, with a population of 35 million.

22 May 2012

Kilauea's Explosive Past - and Future

The explosive history of Kilauea is not well known. Today, it’s renowned for lobes of slow-moving, calm lava, which ooze out of cracks in the flanks of the volcano, pour downslope and eventually flow into the sea, where the lava cools and gradually enlarges the island. But in the past, Kilauea has erupted violently — more often and for much longer periods than was previously thought. Now, researchers have learned that over the past 2,500 years, violent eruptive periods lasting centuries have alternated with periods of quiet flows. Once an explosive period has begun, conditions on the Big Island will be very different from those on which the past hazard assessment was based.

17 May 2012

Mobile mapping with lidar hits the road

About a decade ago, Light Detection and Ranging technology, also known as lidar, burst onto the geoscience scene. The tool was quickly adopted by researchers, from archaeologists and geomorphologists to seismologists and atmospheric scientists.

By mounting lasers and detection and positioning instruments on an airplane or satellite, researchers could map everything from Mayan ruins lost beneath thick jungle canopies to erosion along shorelines to the structure of particulate plumes emitted from power plants to the topography of entire countries.

26 Apr 2012

Managing the seismic risk posed by wastewater disposal

From an earthquake perspective, 2011 was a remarkable year. While the devastation accompanying the magnitude-9.0 Tohoku earthquake that occurred off the coast of Japan on March 11 still captures attention worldwide, the relatively stable interior of the U.S. was struck by a somewhat surprising number of small-to-moderate earthquakes that were widely felt. Most of these were natural events, the types of earthquakes that occur from time to time in all intraplate regions.

17 Apr 2012

U.S. Navy navigates a sea change in the Arctic

Arctic sea ice is already significantly declining in both extent and thickness, and impacts of the decline are evident. New shipping lanes in the Northwest Passage have been passable for ship traffic during summer months for the last two years, and an increasingly accessible Arctic is attracting increased interest. Shipping companies, entrepreneurs, scientists and tourists, however, are not the only ones looking north; militaries around the world, including the U.S. Navy, also have an interest. To that end, the Navy has created a task force and employed a corps of geoscientists to help develop a roadmap for expected future Arctic operations.

16 Apr 2012

IceGoat: The next generation

One source of young talent to carry the military’s proposals and technologies into the future will come from the U.S. Naval Academy in Annapolis, Md., where Lt. Cmdr. John Woods, an oceanography professor, specializes in sea-ice studies. Woods recently launched a polar science program, supported by the academy’s STEM Office, which he hopes will convey to students an understanding of sea-ice dynamics — how ice is thinning and what’s causing it to thin.

16 Apr 2012

Danger in paradise: The hidden hazards of volcano geotourism

In November 2000, rangers at Hawaii Volcanoes National Park made a gruesome discovery. The bodies of a man and a woman, in an advanced state of decomposition, were found near the site where lava from the Kilauea eruption flows into the sea, sending up plumes of scalding white steam. The area, aptly named the Eruption Site, is littered with chunks of tephra, a glassy volcanic rock, which are formed and ejected violently into the air when the 2,000-degree-Celsius lava is quenched by seawater.

19 Mar 2012

Listening for gas bubbles

Passive acoustic technology detects natural gas leaks and seeps

In recent decades, active acoustic surveys have been used to detect methane seeps and gas hydrates — deposits of crystalline solids consisting of gas molecules, usually methane, surrounded by a cage of water molecules — buried under the seafloor.

27 Feb 2012

Gold, lead and death in Nigeria

Geology, economics and culture culminate in a perfect storm with deadly results

20 Feb 2012

Dangerous dust: Erionite - an asbestos-like mineral causing a cancer epidemic in Turkey - is found in at least 13 states

As North Dakota’s state geologist, Ed Murphy has spent a fair amount of time mapping the geology of the Killdeer Mountains in the western part of the state, hiking up and down buttes of the White River Group and the Arikaree Formation. In the 1980s, he and colleagues mapped large deposits of rocks bearing erionite — a zeolite mineral formed when volcanic ash is altered by water — that may have had some commercial use.

31 Jan 2012

Pages