Subscribe to our free daily newsletters
. Earth Science News .

Subscribe to our free daily newsletters

SMU seismology research shows North Texas earthquakes occurring on 'dead' faults
by Staff Writers
Dallas TX (SPX) Nov 30, 2017

The post-2008 seismicity has occurred both in areas that were seismically active before 2008 (for example, the Mississippi embayment) and in regions with no pre-2008 historical or instrumental seismicity (for example, FWB). The two study areas are outlined and represented in Figs. 2 and 6.

Recent earthquakes in the Fort Worth Basin - in the rural community of Venus and the Dallas suburb of Irving - occurred on faults that had not been active for at least 300 million years, according to research led by SMU seismologist Beatrice Magnani.

The research supports the assertion that recent North Texas earthquakes were induced, rather than natural - a conclusion entirely independent of previous analyses correlating seismicity to the timing of wastewater injection practices, but that corroborates those earlier findings.

"To our knowledge this is the first study to discriminate natural and induced seismicity using classical structural geology analysis techniques," said Magnani, associate professor of geophysics in SMU's Huffington Department of Earth Sciences. Co-authors for the study include Michael L. Blanpied, associate coordinator of the USGS Earthquake Hazard program, and SMU seismologists Heather DeShon and Matthew Hornbach.

The results were drawn from analyzing the history of fault slip (displacement) over the lifetime of the faults. The authors analyzed seismic reflection data, which allow "mapping" of the Earth's subsurface from reflected, artificially generated seismic waves.

Magnani's team compared data from the North Texas area, where several swarms of felt earthquakes have been occurring since 2008, to data from the Midwestern U.S. region that experienced major earthquakes in 1811 and 1812 in the New Madrid seismic zone.

Frequent small earthquakes are still recorded in the New Madrid seismic zone, which is believed to hold the potential for larger earthquakes in the future.

"These North Texas faults are nothing like the ones in the New Madrid Zone - the faults in the Fort Worth Basin are dead," Magnani said. "The most likely explanation for them to be active today is because they are being anthropogenically induced to move."

In the New Madrid seismic zone, the team found that motion along the faults that are currently active has been occurring over many millions of years. This has resulted in fault displacements that grow with increasing age of sedimentary formations.

In the Fort Worth Basin, along faults that are currently seismically active, there is no evidence of prior motion over the past (approximately) 300 million years. "The study's findings suggest that that the recent Fort Worth Basin earthquakes, which involve swarms of activity on several faults in the region, have been induced by human activity," said USGS scientist Blanpied.

The findings further suggest that these North Texas earthquakes are not simply happening somewhat sooner than they would have otherwise on faults continually active over long time periods. Instead, Blanpied said, the study indicates reactivation of long-dormant faults as a consequence of waste fluid injection.

Seismic reflection profiles in the Venus region used for this study were provided by the U.S. Geological Survey Earthquake Hazards Program. Seismic reflection profiles for the Irving area are proprietary. Magnani and another team of scientists collected seismic reflection data used for this research during a 2008-2011 project in the northern Mississippi embayment, home to the New Madrid seismic zone.

Research Report: "Discriminating between natural vs induced seismicity from long-term deformation history of intraplate faults,"

New Zealand says no charges over killer quake building
Wellington (AFP) Nov 30, 2017
New Zealand police on Thursday ruled out laying criminal charges over the catastrophic collapse of a office block that claimed 115 lives in the 2011 Christchurch earthquake. The CTV building crumpled then burst into flames after the 6.3-magnitude tremor on February 22, 2011, killing those trapped inside, including 65 foreign students mainly from Japan and China. After a four-year invest ... read more

Related Links
Southern Methodist University
Bringing Order To A World Of Disasters
When the Earth Quakes
A world of storm and tempest

Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once

credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly

paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

Beijing evicts migrants onto cold streets, sparking outcry

Russia opens commission into 'nuclear incident' report

Seven 'trapped' after cargo ships collide off south China

China port city blast caused by illegal explosives: police

New way to write magnetic info could pave the way for hardware neural networks

Device could reduce the carbon footprint of ethylene production

Researchers inadvertently boost surface area of nickel nanoparticles for catalysis

X-rays reveal the biting truth about parrotfish teeth

Why are there no sea snakes in the Atlantic?

The world needs to rethink the value of water

Scientists discover resilient 'heart' of Great Barrier Reef

Children who avoid tap water have lower lead levels but more tooth decay

Antarctic Selfie's Journey to Space via Disruption Tolerant Networking

Antarctic landscape insights keep ice loss forecasts on the radar

Operation IceBridge 2017: The Beauty of Ice

Added Arctic data shows global warming didn't pause

Istanbul anglers keep up tradition despite stocks alarm

Gene discovery may halt worldwide wheat epidemic

Genome of wheat ancestor sequenced

Fighting plant disease at warm temperatures keeps food on the table

Indonesia reopening Bali airport shut by volcanic ash fears

New Zealand says no charges over killer quake building

Bali volcano burns wedding dreams, threatens economy

16 dead, 100 missing as cyclone hits India, Sri Lanka

Mali justice minister resigns after activist's acquittal

Cash and history keep Europe as Africa's prime partner

China hails new Zimbabwe leader, denies role in transition

China taps Africa at Morocco Silk Road investment forum

Long-term logging study demonstrates impacts on chimpanzees and gorillas

Chimp females who leave home postpone parenthood

What grosses out a chimpanzee?

Human evolution was uneven and punctuated, suggests new research

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement