Subscribe to our free daily newsletters
. Earth Science News .




Subscribe to our free daily newsletters



SHAKE AND BLOW
From where will the next big earthquake hit the city of Istanbul
by Staff Writers
Potsdam, Germany (SPX) May 18, 2017


Marmara Sea region in northwestern Turkey with the North Anatolian Fault Zone (NAFZ) separating Eurasia from Anatolian. The offshore Marmara fault where a major earthquake is overdue is indicated by the red line. The black lines to either side are the two last major ruptures of the region, the 1912 Ganos and the 1999 Izmit earthquakes. The Marmara section has not produced a large earthquake since 1766 but is know to rupture every ~250 years based on historical records. The yellow stars mark the repeating earthquakes found in the now published study indicating fault creep (green rectangle) while the fault portion offshore of Istanbul (blue rectangle) is locked. Image courtesy Christopher Wollin/GFZ.

The city of Istanbul is focus of great concern for earthquake researchers. This 15-million metropole is situated very close to the so-called North Anatolian Fault Zone which runs just outside of the city gates below the Marmara Sea. Here in the underground there is a constant build-up of energy which results from an interlocking of the tectonic plates causing plate movement to come to a halt until a great tremor releases this energy. Scientists, therefore, reckon with an earthquake with a magnitude of 7 or greater in this region in the coming years.

The extent of such seismic threat to this Turkish city of Istanbul actually depends on how strongly the plates are entangled and on the exact nucleation point of the earthquake. A team led by Marco Bohnhoff from the GFZ German Research Centre for Geoscience now presents a study indicating that the next major earthquake is more likely to originate in Istanbul's eastern Marmara Sea.

"This is both good news and bad news for the city with over 15 million inhabitants. The good news: "The rupture propagation will then run eastwards i.e. away from the city", explains the researcher.

"The bad news is that there will only be a very short early warning phase of a few seconds." Early warning times are extremely important in order to switch traffic lights to red, to block tunnels and bridges or to shut down critical infrastructure. The research results are now published in the scientific journal "Geophysical Journal International".

The estimations presented by Marco Bohnhoff and his team are based on the analysis of numerous small quakes along the Marmara fault. Results have shown that the degree of locking in the western part of the fracture zone is lower and that the two tectonic plates are creeping past one another at a very slow rate.

During this process small tremors of the same signature, so-called "repeaters", occur at distinct recurrence times. Further east, close to Istanbul, however, repeaters have not been observed and the tectonic plates appear to be completely locked here. This leads to a build-up of tectonic energy and increases the probability of a large earthquake there.

Such observations were possible due to a new high-precision seismicity catalog for the region. For this purpose, the researchers have thoroughly evaluated the earthquake activity by combining the two major Turkish Earthquake Measurement Networks with measurement data from the GFZ Plate Boarder Observatory within the framework of a German-Turkish cooperation project.

"In this way we have found recurring earthquakes below the western Marmara Sea" says Bohnhoff. "From this we deduce that below the western Marmara Sea the two tectonic plates (for the most part - 25-75%) are moving slowly past each other thus accumulating less energy than if they were completely locked."

And what will happen if it actually comes to the feared strong earthquake below the western Marmara Sea? "In such a case there would likewise be good news and bad news," says Bohnhoff.

Good would be a somewhat longer early warning period, bad would be the fact that the rupture propagation would then take place in the direction of Istanbul resulting in more severe ground shaking than if the origin was further east. However, the current data obtained suggests the opposite: an earthquake with an epicenter at the gates of the city, which would allow the people only very little time to find protection, but which would trigger less powerful ground movements.

Research paper

SHAKE AND BLOW
Quake kills two, injures hundreds in Iran: state media
Tehran (AFP) May 14, 2017
A 5.7 magnitude earthquake near Iran's border with Turkmenistan killed two people, injured hundreds and caused widespread damage, state media reported Sunday, citing the country's seismological centre. The quake, which struck at 1800 GMT Saturday in and around the city of Bojnurd, North Khorasan province, killed a 54-year-old woman and a teenage girl, ISNA news agency reported. It left m ... read more

Related Links
GFZ GeoForschungsZentrum Potsdam, Helmholtz Centre
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
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

SHAKE AND BLOW
Countries most affected by weather disasters do not spend more on weather services

Trump budget calls for deep cuts to social safety net

Massive slide buries stretch of iconic California highway

58,000 Haitians facing deportation get US extension

SHAKE AND BLOW
Physicists discover mechanism behind granular capillary effect

HPC4MfG paper manufacturing project yields first results

Unfolding the folding mechanism of ladybug wings

Using light to rearrange macroscopic structures

SHAKE AND BLOW
Water is surprisingly ordered on the nanoscale

Sentinel-2 captures coral bleaching of Great Barrier Reef

Heat on for Australia's Great Barrier Reef as temperatures rise

Dams are major driver of global environmental change

SHAKE AND BLOW
China says no mining planned in Antarctica

NASA's Arctic Ecosystem Science Flights Begin

Elevation could help explain why Antarctica is warming slower than Arctic

NASA Annual Arctic Ice Survey Expanded Range This Year

SHAKE AND BLOW
Popular artificial sweetener also works as pesticide and insect birth control

Helping plants pump iron

Blue and purple corn: Not just for tortilla chips anymore

Diverse rotations and poultry litter improves soybean yield

SHAKE AND BLOW
Researchers discover hottest lavas that erupted in past 2.5 billion years

Mexico next in line to examine geothermal energy

New study documents aftermath of a supereruption

From where will the next big earthquake hit the city of Istanbul

SHAKE AND BLOW
Angry Ivory Coast ex-rebels block access to cities

Nigeria seizes illegal arms shipment

Congo breaks ground on $58 million China-funded parliament building

Four killed in I.Coast clashes between ex-rebels and police

SHAKE AND BLOW
Portions of human skeletal structure were established millions of years earlier than previously thought,

Study reveals architecture of the 'second brain,' the enteric nervous system

'Moral enhancement' technologies are neither feasible nor wise

Adolescent orangoutan breastfeed for eight years




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