Taxonomy term

seismicity

Injection experiment offers new view of fluid-filled faults

Scientists have known since the late 1960s that injecting fluids underground can cause earthquakes if those fluids find their way into slip-prone fault zones. Evidence of fluid-induced quakes has continued mounting in recent years with observations of abnormally high levels of seismicity in the central U.S., coincident with increased injections of wastewater into the ground — mostly related to oil- and gas-mining operations. But understanding the inner workings of fluid-filled faults is challenging because researchers have been limited by how close they can get to study them. Now, a new study is offering a glimpse into the future of induced-seismicity studies by monitoring fault motions on the spot and in real time.
 
19 Sep 2015

Down to Earth With: Marine Geophysicist Maya Tolstoy

Growing up in Scotland, Maya Tolstoy was drawn to the theater, and even briefly considered majoring in the subject in college. Instead, she chose to follow another lifelong passion and became a marine geophysicist.

21 May 2015

Ground-shaking research: How humans trigger earthquakes

An uptick in the occurrence of earthquakes in places where they used to be rare — like Oklahoma, where waste-fluid injection is triggering frequent quakes — prompts a look at the many ways humans can and do induce seismicity.

05 Apr 2015

Superquakes, supercycles, and global earthquake clustering: Recent research and recent quakes reveal surprises in major fault systems

A number of recent big earthquakes around the world have humbled many earthquake researchers. The March 2011 magnitude-9 superquake off Tohoku, Japan, and the December 2004 magnitude-9-plus temblor off Sumatra were both far larger than what scientists expected those fault systems to produce. Based on these quakes, and on recent research that contradicts long-held paradigms, it is becoming clear that the types and sizes of large earthquakes that a given fault system is capable of producing remain poorly known for most major fault systems.

07 Jan 2013

Blame it on the rain: The proposed links between severe storms and earthquakes

 

The U.S. Geological Survey’s website states it in no uncertain terms: “There is no such thing as ‘earthquake weather.’” Not too surprising, right? After all, how could the seemingly insignificant stresses imposed on the planet’s surface by mere weather instigate seismic shaking far underfoot?  Earthquakes and heavy rainstorms do occasionally produce comparable results on the planet’s surface, devastating landscapes and impacting humans, but it’s hard to imagine any more of a connection between such disparate phenomena. Yet, from at least the time of Aristotle, some people have professed links between atmospheric conditions and seismic shaking. And as the ability to record Earth’s rumblings has continued to improve, efforts to demonstrate such links scientifically have persisted into the present century.

23 Oct 2012

On the web: Shake, rattle and roll: What does an earthquake sound like?

The sounds we associate with earthquakes tend to be those induced aboveground. Low-pitched rumbles, rattling windows and car alarms might be heard during small temblors, while more terrifying sounds like the crumbling of concrete and the cacophony of people trying to reach safety sometimes accompany large earthquakes. But what does an earthquake itself sound like, as rock grinds against rock in a rupturing fault and large amounts of energy are released? Thanks to some recent efforts, we may be starting to get an idea.
 

08 Aug 2012

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