Taxonomy term

february 2019

Free swimmers came back first after Great Dying

About 252 million years ago, at the boundary between the Permian and Triassic periods, the vast majority of marine and terrestrial life died out in the most devastating extinction event in Earth’s history. Earth’s ecosystems eventually recovered, but not in the way — or as quickly as — scientists thought. In a new study looking at how marine species reemerged in the Triassic, researchers report a surprising trend of recovery from the top of the food chain down.

14 Feb 2019

Geologic Column: Is this land really your land?

In 1940, Woody Guthrie wrote the iconic folk song, “This Land Is Your Land,” as a commentary on inequality. Where do we stand today, and who really owns the land in America?

13 Feb 2019

Archaeologists hit pay dirt in medieval latrines

Archaeologists digging in Lübeck, Germany, unearthed an unusual source of information about past dietary habits in the city: parasite eggs recovered from 700-year-old latrines.

12 Feb 2019

Sounding Out Earth's Hum

Scientists are working to isolate and identify the various sources and mechanisms, beyond earthquakes, that vibrate the solid earth. The search has led them offshore to investigate how wind and waves and the seafloor interact to produce a symphony of sound that humans can’t hear.

11 Feb 2019

Hot but not bothered: Warm soils favor microbes with small genomes

Centralia, Pa., sits above rich subterranean coal seams, which made the town a mining center for about a century. In 1962, the seams were accidentally ignited by burning garbage, turning the coal from a commodity into a liability. Driven away by fire-associated hazards and particulate air pollution, all but a few human residents have long since abandoned the town. However, a new study reveals that the same isn’t true for all forms of life: A diverse population of microbial life resides in Centralia’s hot soils. These heat-tolerant microbes are offering scientists novel insights into the composition and character of soil microbial communities and resilience in response to dramatic ecosystem change.

08 Feb 2019

Mediterranean heritage sites threatened by rising seas

The Mediterranean region has been a cultural center for centuries, giving rise to numerous locales designated as UNESCO World Heritage sites. A new study looking at the effects of rising sea levels on treasures like the Venetian Lagoon, the Old City of Dubrovnik and the ruins of Carthage indicates that most UNESCO sites on the Mediterranean Sea are at risk of storm surge and coastal erosion as well as inundation in the coming decades.

07 Feb 2019

Comment: Faster flood forecasting to improve responses

High-resolution weather models can generate very accurate forecasts, but they take time to run — time that may be needed to safely respond to a rapidly unfolding weather disaster. The authors examine the tradeoffs between accuracy and timeliness in flood forecasting.

06 Feb 2019

Mighty Mekong cut by monsoon, not tectonics

The rivers draining the Tibetan Plateau are some of the largest, longest and most deeply incised waterways in the world. For decades, most geologists assumed that these river canyons were cut as the plateau was uplifted following the initial collision of the Indian subcontinent with Asia. However, recent studies have found that the plateau was already elevated by 40 million years ago — roughly 20 million years before the deep canyons formed. 

06 Feb 2019

"Cradle of Humankind" fossils can now be dated

Robyn Pickering was taught as an undergraduate about a collection of limestone caves in northern South Africa known collectively as the Cradle of Humankind for the trove of early hominin fossils discovered there. She learned that, unlike hominin fossils unearthed in East Africa, whose ages have been constrained by dating the surrounding layers of volcanic ash, the fossils in the Cradle — including well-preserved specimens of Australopithecus africanus and the recently discovered Homo naledi, among others — were impossible to date independently. Now, Pickering, an isotope geochemist at the University of Cape Town, and her colleagues have figured out a way to date the South African fossils after all. In a recent study published in Nature, the researchers report ages for flowstones — horizontal deposits of calcium carbonate that form natural cements on cave floors — across eight caves in the Cradle of Humankind. The flowstones sandwich fossil-bearing sediment layers, allowing age ranges for the fossils to be determined.

05 Feb 2019

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