Taxonomy term


Water weight and surface rebound trigger small quakes in California

On average, a cubic meter of snow weighs less than 100 kilograms, but heavy, compacted snow can weigh more than 500 kilograms per cubic meter, with glacial ice approaching 900 kilograms per cubic meter. In California, as elsewhere, the weight of winter snow and spring runoff pushes down on the landscape, affecting stresses on fault systems, which may trigger small quakes. As the snow melts and the runoff makes its way downstream, land rebounds, setting off more small earthquakes.

12 Oct 2017

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

Comment: Atmospheric rivers increase water supply in California — but only to a point

Atmospheric rivers can cause floods; their absence can cause droughts. How can water managers adapt to capture and store floodwaters brought by these enormous storms for later use?

10 Feb 2017

Robotic mussels track temperature change

Among the crashing waves of rocky shorelines, tiny robotic mussels are providing scientists with insight into climate change impacts on marine life. The battery-powered “biomimics” hide among real mussels, with internal thermometers to estimate temperatures of their nearby living neighbors. Mussels’ body temperatures are changing with solar radiation, cloud cover and wind speed, says Brian Helmuth, a marine ecologist from Northeastern University in Boston. Because of this, the mussels’ body temperatures are generally much higher than the temperature of the surrounding air during exposure at low tide.

01 Feb 2017

California drought stops slow-moving landslides

Most people think of landslides as fast-moving events, but many slides creep slowly, advancing over hundreds or thousands of years. In a new study, researchers looking at creeping landslides in California have revealed an unexpected consequence of the state’s ongoing drought: Many of the slides have nearly stopped due to the lack of water in the soil.

27 Sep 2016

Ocean acidification worsens overnight along California coast

Carbon dioxide absorbed by the oceans causes seawater to become more acidic, which, as scientists have long been documenting, can negatively impact marine animals; for example, acidified waters damage the calcite skeletons and shells of organisms like coral, mussels and oysters by causing them to dissolve. In a new study, scientists have found that ocean seawater acidification may also be taking a toll on shelled organisms like coralline algae, bivalves and gastropods residing in tide pools along California’s coastlines.

29 Jul 2016

Benchmarks: July 26, 1905: The rising Salton Sea swamps the Southern Pacific Railroad

On a scorching summer day in 1905, in the middle of a desert, the Colorado River, which had broken free from an irrigation canal and found its way to the lowest point around — the Salton Sink — swamped the Southern Pacific Railroad. Bounded by the Mojave Desert to the north and the Sonoran Desert to the south, the sink lies 70 meters below sea level at the bottom of the Salton Trough. By the time the railroad sealed the breach 18 months later, the Salton Sea stretched 58 kilometers long and 42 kilometers wide, making it California’s largest lake.

26 Jul 2016

Geomedia: Books: 'Floodpath' recounts the deadly collapse of California's St. Francis Dam

The catastrophic collapse of the St. Francis Dam, located 80 kilometers north of downtown Los Angeles and east of the town of Santa Clarita, just before midnight on March 12, 1928, claimed more than 400 lives when towering floodwaters destroyed homes, bridges and farmland, as they swept through downstream communities. The disaster was initially blamed on the failure of the west abutment, anchored in soft conglomerate rock. Additional studies have revised this explanation, with recent research citing other geologic and design factors that likely contributed. Regardless, the collapse effectively ended the career of William Mulholland, the self-taught engineer whose 1913 Owens Valley Aqueduct made the explosive growth of Los Angeles possible. Yet, despite the magnitude of the disaster and its impact on local and national policy, it has been almost entirely forgotten, except by a few historians.

08 Jun 2016

The most dangerous fault in America

Running through densely populated cities like Oakland, Fremont and Berkeley, Calif., and not far from San Francisco, San Jose and Silicon Valley is a dangerous fault that could rupture at any time. It’s known as the Hayward Fault, and when it goes, it will likely produce a devastating earthquake.

18 May 2016

Protracted drought threatens California levees

Levee failures are most often associated with the onslaught of water from large storms, such as Hurricane Katrina, whose landfall in 2005 caused more than 50 floodwalls and levees around New Orleans to fail.

But the lack of water can also weaken these critical earthen structures, according to recent research presented last December at the fall meeting of the American Geophysical Union in San Francisco. 

15 Mar 2016