Taxonomy term

lauren milideo

Nineteenth-century cows muddied Southern California continental shelf

When offshore ecosystems deteriorate, scientists often look at changing ocean conditions, urban runoff or fishing as potential explanations. Cows usually don’t come to mind. But new research investigating the seafloor off the coast of Los Angeles suggests that 19th-century cattle, despite their terrestrial lifestyle, left a lasting impact on the underwater habitat there.

26 Jul 2017

Cave dripwater records wildfires

Water seeps through soil and bedrock before dripping from the roof of a cave and carries with it elements of the outside world and its climate history. That is why speleothems, cave structures formed via precipitation, can be studied as climate proxies. New research suggests that the chemistry of the cave dripwater can also contain the signature of wildfires that burned outside the cave, on the ground above the cave’s roof, yielding a more complex picture of the past.

27 Oct 2016

Earthworms build big mounds to escape floodwaters

When researchers looking for archaeological remains in satellite imagery came across unidentified mounds — some as tall as humans — in the seasonally flooded wetlands of northern South America, they found a landscape shaped not by ancient civilizations but, rather, by modern earthworms.

26 Aug 2016

North Sea uplift caused Jurassic cooling event

The climate of the Jurassic, long envisioned as ubiquitously warm from the equator to the poles, was actually more dynamic, sometimes cooling dramatically, according to a new study. The research joined isotopic and sedimentological data to suggest that an abrupt cooling event occurred in the midlatitudes early in the Middle Jurassic as a result of changing ocean currents associated with a feature known as the North Sea Dome.

31 Mar 2016

Revealing potential tsunami inundation on California coast

Earthquakes are well known along Southern California’s coast, and existing hazard maps indicate where quake-triggered tsunamis could flood the coastline. But in a new modeling study published in Geophysical Research Letters, researchers found that an earthquake-generated tsunami northwest of Los Angeles may reach farther inland than is currently projected.
 
06 Feb 2016

Ocean oxygen levels control seafloor carbon burial

Residual organic carbon from dead marine phytoplankton and other oceanic life can follow two pathways: It can be deeply buried in seafloor sediments or it can be oxidized, either in the water column or in shallow sediment layers. The balance between these two processes and the extent of organic carbon burial over time are crucial in the global carbon cycle, but a complete understanding of the factors and rates controlling organic carbon burial versus oxidation in the oceans has been lacking. In a recent study in Geology, scientists improved on an approach to quantify organic carbon oxidation and provided a glimpse of marine organic carbon burial in the Precambrian, when the oceans were anoxic and Earth’s atmosphere was in the early stages of oxygenation.
 
05 Dec 2015

Old piles of shells reveal ancient El Niño patterns

Understanding of the El Niño-Southern Oscillation (ENSO) is evolving as scientists unearth new data sources. In a study recently published in Science, scientists turned to the discarded remains of shellfish for a 10,000-year record of eastern Pacific ENSO activity, which offered glimpses into unexpected past ENSO behavior and intensity.

03 Jan 2015

Infrasound reveals lava lake levels

The rises and falls of volcanic lava lakes are not easily tracked, especially when the lakes aren’t visible from crater rims. But recently, researchers found a way to monitor the lava lake at Chile’s Villarrica volcano using complementary methods to keep an eye on a feature they can’t always see.

22 Aug 2014

Magma mobilizes quickly beneath Mount Hood

In a recent study in Nature, researchers found that magma beneath Oregon’s Mount Hood spends minimal time in an eruptible state. Instead, magma remobilization and eruption occur within a short time frame. What this means for volcanic hazards in the Pacific Northwest has yet to be determined. 

10 Jun 2014

Fieldwork revises ice-free corridor hypothesis of human migration

The existence of an ice-free corridor through Canada during  the climax of last glaciation, which allowed the first Americans to cross the Bering land bridge from Siberia and move south (about 13,000 years ago), has long been postulated in North American archaeology. Now, research based on the exposure ages of glacial rocks found in the corridor suggests a puzzling conclusion — that the open pathway closed several thousand years prior to 20,000 years ago and didn’t open again until between 13,000 and 12,000 years ago, well after  first Americans were in the Americas.

13 Apr 2014

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