3D magnetotelluric imaging reveals magma recharging beneath Weishan volcano

June 28, 2020

A collaborative research team from University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS) and China Geological Survey (CGS) have succeeded in obtaining a high-resolution 3D resistivity model of approximately 20 km depth beneath the Weishan volcano in the Wudalianchi volcanic field (WVF) for the first time. The study, published in Geology, revealed the image of potential magma chambers and the estimated melt fractions.

WVF in the northeast of China, comprised of 14 volcanoes that have erupted about 300 years ago, is one of the largest active volcanic areas. Volcanic activities are hazard to human life and have severe environmental consequences, thus it is important to characterize the magmatic system beneath the volcanoes to understand the nature of the eruption.

In conjunction with the Center for Hydrogeology and Environmental Geology, CGS, Prof. ZHANG Jianghai's group from School of Earth and Space Sciences, USTC, utilized magnetotelluric (MT) methods to image magma reservoirs beneath Weishan volcano and obtained its high-resolution spatial resistivity distribution up to 20 km deep. Their findings showed the existence of vertically distributed low-resistivity anomalies that are narrowest in the middle. This was further interpreted as magma reservoirs existing both in the upper crust and the middle crust, which are linked by very thin vertical channels for magma upwelling.

Meanwhile, they cooperated with Institute of Geodesy and Geophysics of CAS, combining both the velocity model from ambient noise tomography (ANT) and the resistivity model from MT imaging to estimate that the melt fractions of the magma reservoirs in the upper crust and the middle crust are reliably to be >~15%. This phenomenon demonstrated that there should be an even deeper source for recharging the magma chambers to keep the melt fraction increasing, and indicated that the volcano is still active.

Considering the significant melt fractions and the active earthquakes and tremors occurred around the magma reservoirs several years ago, the Weishan volcano is likely in an active stage with magma recharging. Although the melt fraction does not reach the eruption threshold (~40%), it is necessary to increase monitoring capabilities to better forecasting its potential future eruptions.

Overall, this study has revealed that the volcanoes in northeast China may be in an active stage. This poses a grave threat to man and environment, thus proper monitoring is required to forecast its hazardous implications.

University of Science and Technology of China

Related Volcano Articles from Brightsurf:

Using a volcano's eruption 'memory' to forecast dangerous follow-on explosions
Stromboli, the 'lighthouse of the Mediterranean', is known for its low-energy but persistent explosive eruptions, behaviour that is known scientifically as Strombolian activity.

Rebirth of a volcano
Continued volcanic activity after the collapse of a volcano has not been documented in detail so far.

Optical seismometer survives "hellish" summit of Caribbean volcano
The heights of La Soufrière de Guadeloupe volcano can be hellish, sweltering at more than 48 degrees Celsius (120 degrees Fahrenheit) and swathed in billows of acidic gas.

Researchers reveal largest and hottest shield volcano on Earth
Researchers from the University of Hawai'i at Mānoa revealed the largest and hottest shield volcano on Earth--Pūhāhonu, a volcano within the Papahānaumokuākea Marine National Monument.

Formation of a huge underwater volcano offshore the Comoros
A submarine volcano was formed off the island of Mayotte in the Indian Ocean in 2018.

Volcano F is the origin of the floating stones
Since August a large accumulation of pumice has been drifting in the Southwest Pacific towards Australia.

Researchers discover a new, young volcano in the Pacific
Researchers from Tohoku University have discovered a new petit-spot volcano at the oldest section of the Pacific Plate.

What happens under the Yellowstone Volcano
A recent study by Bernhard Steinberger of the German GeoForschungsZentrum and colleagues in the USA helps to better understand the processes in the Earth's interior beneath the Yellowstone supervolcano.

Geoengineering versus a volcano
Major volcanic eruptions spew ash particles into the atmosphere, which reflect some of the Sun's radiation back into space and cool the planet.

How to recognize where a volcano will erupt
Eleonora Rivalta and her team from the GFZ German Research Centre for Geosciences in Potsdam, together with colleagues from the University Roma Tre and the Vesuvius Observatory of the Italian Istituto Nazionale di Geofisica e Vulcanologia in Naples have devised a new method to forecast volcanic vent locations.

Read More: Volcano News and Volcano Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.