Subscribe to our free daily newsletters
. Earth Science News .




Subscribe to our free daily newsletters



SHAKE AND BLOW
Satellites shed new light on earthquakes
by Staff Writers
Paris (ESA) Mar 27, 2017


A 7.8-magnitude earthquake struck New Zealand's South Island near the town of Kaikoura on 14 November 2016. Satellite radar images from the Copernicus Sentinel-1 and Japanese ALOS-2 missions were used to measure the extent of the land movement. In this figure, derived from Sentinel-1 data, the colours show the amount of uplift or subsidence that occurred, and the arrows show the horizontal movement. Image courtesy Copernicus Sentinel data (2016), processed by COMET. For a larger version of this image please go here.

Satellite radar scans of last year's earthquake in New Zealand are changing the way we are thinking about earthquake hazards in regions where our planet's tectonic plates meet.

The 7.8-magnitude quake that struck New Zealand's South Island near the town of Kaikoura on 14 November was one of the most comprehensively recorded earthquakes in history.

Immediately after it, a team of scientists from New Zealand, the UK and the US began to study radar images from the Copernicus Sentinel-1 and Japanese ALOS-2 missions to measure the extent of the land movement.

They found that the quake caused the ground to rise by 8-10 m and offset features like roads that crossed the fault by up to 12 m. This caused large landslides and triggered a tsunami.

Satellite radar scans from before and after the quake showed that the ground-based seismic readings were not giving accurate assessments of where the ruptures were occurring.

Seismic readings are based on the shockwaves rippling through Earth. Although they are the quickest way to gather information on earthquakes, they are unable to show details in complex quakes like Kaikoura.

But radar satellites like Sentinel-1 can detect movements of millimetres in the ground and across wide areas, providing a detailed picture of land deformation and the locations of fault lines.

In the case of Kaikoura, it showed the research team that ruptures took place across many separate faults.

They saw that the complexity and large amount of uplift point towards how mountains in regions such as New Zealand could build rapidly.

"We've never seen anything like the Kaikoura quake before - it was one of the most complex ever recorded," said Professor Tim Wright, study co-author and director of the Centre for the Observation and Modelling of Earthquakes, Volcanoes and Tectonics at the UK's University of Leeds.

"An earthquake commonly ruptures across a single fault line or faults that are closely grouped, but Kaikoura ruptured at least 12 major crustal faults across two distinct active fault domains.

"This challenges many assumptions about how individual faults control earthquake ruptures."

The study published yesterday in Science has prompted scientists to reassess how many different faults can be involved in a single earthquake, and could potentially help to re-evaluate seismic hazard models.

"There was growing evidence internationally that conventional seismic hazard models are too simple and restrictive," said Dr Ian Hamling, a natural hazards geodesist from New Zealand research institute GNS Science and the lead author of the study.

"The message from Kaikoura is that earthquake science should be more open to a wider range of possibilities when rupture models are being developed. It underlines the importance of re-evaluating how rupture scenarios are defined for seismic hazard models. "

New Zealand's complex network of faults is similar to those found in western US, Japan and central Asia.

"While earthquakes like Kaikoura's do not commonly occur, the data we've gathered from this event will expand our understanding of similar boundary zones around the world," said Dr John Elliott from Leeds' School of Earth and Environment, and co-author.

"Not only could the data help inform us for the future but it may change how we've interpreted ancient earthquakes.

"If an earthquake like Kaikoura's took place thousands of years ago, current methods of paleoseismology would possibly see it as a series of earthquakes over a long period of time, rather than as one large single quake."

Research paper

SHAKE AND BLOW
Dissection of the 2015 Bonin deep earthquake
Sendai, Japan (SPX) Mar 17, 2017
Researchers at Tohoku University's Department of Geophysics, have been studying the deep earthquake which occurred on May 30, 2015, to the west of Japan's Bonin Islands. The earthquake, which registered at about 670 km depth with moment magnitude (Mw) of 7.9 (Fig. 1), was the deepest global seismic event on record with M = 7.8. It was also an isolated event located over 100 km deeper than ... read more

Related Links
Sentinel-1 at ESA
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
SES is enabling disaster response and connecting affected communities

Japan court rules government liable for Fukushima disaster

In Iraq's Mosul, a school becomes a field hospital

HRW calls on Iraqis to avoid ad hoc mass grave exhumations

SHAKE AND BLOW
Why water splashes: New theory reveals secrets

Pulverizing electronic waste is green, clean - and cold

Scientists aim to create self-propelling liquid, a new kind of matter

Visualizing nuclear radiation

SHAKE AND BLOW
India grants sacred rivers status of 'legal persons'

Brexit plunges EU fishing into troubled waters

Study of non-rainfall water in Namib Desert reveals unexpected origins

Dead zones may threaten coral reefs worldwide

SHAKE AND BLOW
Photographer captures world's glacier melt over decade

Researchers ponder conundrum of disappearing Arctic caribou

Sea ice extent sinks to record lows at both poles

How to conserve polar bears and maintain subsistence harvest

SHAKE AND BLOW
Almond-crop fungicides are harmful to honey bees

Brazil tainted meat: Three key markets resume imports

New Zealand's 'green' image under threat: OECD

China bans Brazil meat in health scare: Brasilia

SHAKE AND BLOW
Rooftop refugees plead for water in flooded Peru city

Flooding kills 11 in Angola

More rain looms as Peru struggles with disastrous floods

Dissection of the 2015 Bonin deep earthquake

SHAKE AND BLOW
Operations against Kony's LRA 'coming to an end': US general

Nigerian rights group denounces 'attacks' on Amnesty office

Rags, not riches, defining Africa's urban explosion

Senegal extradites Guinean soldier wanted over massacre

SHAKE AND BLOW
Human skull evolved along with two-legged walking, study confirms

Nose form was shaped by climate

Human skull and bipedalism evolved side-by-side

Indonesian tribes gather amid push to protect homelands




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