Nav: Home

Groundwater helium level could signal potential risk of earthquake

November 29, 2016

Japanese researchers have revealed a relationship between helium levels in groundwater and the amount of stress exerted on inner rock layers of the earth, found at locations near the epicenter of the 2016 Kumamoto earthquake. Scientists hope the finding will lead to the development of a monitoring system that catches stress changes that could foreshadow a big earthquake.

Several studies, including some on the massive earthquake in Kobe, Japan, in 1995, have indicated that changes to the chemical makeup of groundwater may occur prior to earthquakes. However, researchers still needed to accumulate evidence to link the occurrence of earthquakes to such chemical changes before establishing a strong correlation between the two.

A team of researchers at the University of Tokyo and their collaborators found that when stress exerted on the earth's crust was high, the levels of a helium isotope, helium-4, released in the groundwater was also high at sites near the epicenter of the 2016 Kumamoto earthquake, a magnitude 7.3 quake in southwestern Japan, which caused 50 fatalities and serious damage.

The team used a submersible pump in deep wells to obtain groundwater samples at depths of 280 to 1,300 meters from seven locations in the fault zones surrounding the epicenter 11 days after the earthquake in April 2016. They compared the changes of helium-4 levels from chemical analyses of these samples with those from identical analyses performed in 2010.

"After careful analysis and calculations, we concluded that the levels of helium-4 had increased in samples that were collected near the epicenter due to the gas released by the rock fractures," says lead author Yuji Sano, a professor at the University of Tokyo's Atmosphere Ocean Research Institute.

Furthermore, scientists estimated the amount of helium released by the rocks through rock fracture experiments in the laboratory using rock samples that were collected from around the earthquake region. They also calculated the amount of strain exerted at the sites for groundwater sample collection using satellite data. Combined, the researchers found a positive correlation between helium amounts in groundwater and the stress exertion, in which helium content was higher in areas near the epicenter, while concentrations fell further away from the most intense seismic activity.

"More studies should be conducted to verify our correlation in other earthquake areas," says Sano. "It is important to make on-site observations in studying earthquakes and other natural phenomena, as this approach provided us with invaluable insight in investigating the Kumamoto earthquake," he adds.
-end-
Journal article:
Yuji Sano, Naoto Takahata, Takanori Kagoshima, Tomo Shibata, Tetsuji Onoue & Dapeng Zhao, "Groundwater helium anomaly reflects strain change during the 2016 Kumamoto earthquake in Southwest Japan", Scientific Reports
URL: https://dx.doi.org/10.1038/srep37939
DOI: 10.1038/srep37939

Collaborating institutions:
Kyoto University, Kumamoto University and Tohoku University

Links:
Atmosphere and Ocean Research Institute, The University of Tokyo

Research contact:
Professor Yuji Sano
Atmosphere and Ocean Research Institute, The University of Tokyo
5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564, Japan
Tel: +81-4-7136-6100
Fax: +81-4-7136-6067
Email: ysano@aori.u-tokyo.ac.jp

Press officer contact:
Yoko Ogawa
Press Office, Atmosphere and Ocean Research Institute, The University of Tokyo
Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8564, Japan
Tel: +81-4-7136-6430
Email:kouhou@aori.u-tokyo.ac.jp

Funding:
This study was partly supported by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan, under its Earthquake and Volcano Hazards Observation and Research Program.

About the University of Tokyo:
The University of Tokyo is Japan's leading university and one of the world's top research universities. The vast research output of some 6,000 researchers is published in the world's top journals across the arts and sciences. Our vibrant student body of around 15,000 undergraduate and 15,000 graduate students includes over 2,000 international students. Find out more at http://www.u-tokyo.ac.jp/en/ or follow us on Twitter at @UTokyo_News_en.

University of Tokyo

Related Stress Articles:

Captive meerkats at risk of stress
Small groups of meerkats -- such as those commonly seen in zoos and safari parks -- are at greater risk of chronic stress, new research suggests.
Stress may protect -- at least in bacteria
Antibiotics harm bacteria and stress them. Trimethoprim, an antibiotic, inhibits the growth of the bacterium Escherichia coli and induces a stress response.
Some veggies each day keeps the stress blues away
Eating three to four servings of vegetables daily is associated with a lower incidence of psychological stress, new research by University of Sydney scholars reveals.
Prebiotics may help to cope with stress
Probiotics are well known to benefit digestive health, but prebiotics are less well understood.
Building stress-resistant memories
Though it's widely assumed that stress zaps a person's ability to recall memory, it doesn't have that effect when memory is tested immediately after a taxing event, and when subjects have engaged in a highly effective learning technique, a new study reports.
Stress during pregnancy
The environment the unborn child is exposed to inside the womb can have a major effect on her or his development and future health.
New insights into how the brain adapts to stress
New research led by the University of Bristol has found that genes in the brain that play a crucial role in behavioural adaptation to stressful challenges are controlled by epigenetic mechanisms.
Uncertainty can cause more stress than inevitable pain
Knowing that there is a small chance of getting a painful electric shock can lead to significantly more stress than knowing that you will definitely be shocked.
Stress could help activate brown fat
Mild stress stimulates the activity and heat production by brown fat associated with raised cortisol, according to a study published today in Experimental Physiology.
Experiencing major stress makes some older adults better able to handle daily stress
Dealing with a major stressful event appears to make some older adults better able to cope with the ups and downs of day-to-day stress.

Related Stress Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Anthropomorphic
Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#SB2 2019 Science Birthday Minisode: Mary Golda Ross
Our second annual Science Birthday is here, and this year we celebrate the wonderful Mary Golda Ross, born 9 August 1908. She died in 2008 at age 99, but left a lasting mark on the science of rocketry and space exploration as an early woman in engineering, and one of the first Native Americans in engineering. Join Rachelle and Bethany for this very special birthday minisode celebrating Mary and her achievements. Thanks to our Patreons who make this show possible! Read more about Mary G. Ross: Interview with Mary Ross on Lash Publications International, by Laurel Sheppard Meet Mary Golda...