Science News - USA (2022-04-23)

26 SCIENCE NEWS | April 23, 2022

FROM TOP: THE DRONAUT/WIKIMEDIA COMMONS (CC BY-SA 4.0); LÁSZLÓ OLÁH AND H.K.M. TANAKA

FEATURE |MUONS OPEN DOORS

Cârloganu thinks muons will be useful for point-

ing out structural weaknesses, but not for giving a

warning when the volcano is going to blow. Other

researchers are more optimistic about muons’

capability for giving timely forewarnings.

Muography is ripe for inclusion in volcano

early-warning systems, Leone, Tanaka and col-

leagues wrote last November in Proceedings of the

Royal Society A. But more work needs to be done

to integrate muography with other established

methods that help warn of an upcoming erup-

tion, Leone says. These methods include seismic

measurements, as well as observations of ground

deformation and volcanic gas emissions.

Tanaka and colleagues are studying Sakurajima,

one of the most active volcanoes in the world,

near Kagoshima, Japan. One of the volcano’s cra-

ters, the Showa crater, erupted frequently until

2017 when the activity abruptly shifted to another

crater, Minamidake. Comparing muography data

taken before and after this shift revealed that a

new, dense region had formed below the Showa

crater, Tanaka and colleagues reported in 2019 in

Geophysical Research Letters. That hints at the rea-

son Showa’s eruptions stopped: It was clogged with

a dense plug of solidified magma, Tanaka says.

These results suggest that scientists can use

muography to help predict volcanic eruptions,

Tanaka says. In fact, using deep learning techniques

on the muography data from Sakurajima, Tanaka

and colleagues reported in Scientific Reports in

2020 that they were able to predict whether the

volcano would erupt the next day, by analyzing

the previous week’s data. The technique correctly

predicted eruption days of the volcano more than

72 percent of the time, and correctly predicted non-

eruption days more than 85 percent of the time.

Just as the discovery of X-rays unveiled a whole

new way of seeing the world, harnessing muons

could change our perspective on our surround-

ings. Attitudes toward a particle once thought

to be unnecessary — unwanted and unloved by

physicists — have been transformed. One day,

perhaps, muons could save lives. s

Explore more

sInternational Muography Research

Organization, University of Tokyo:

http://www.muographix.u-tokyo.ac.jp

sSilent Border: silentborder.eu

Muography revealed a

newly formed plug of

denser material (red

oval) below the Showa

crater of the Sakurajima

volcano in Japan. This

muo graphy image, made

with data taken in 2018

and overlaid on a photo

of the volcano, hinted at

why the crater stopped

erupting. Redder colors

indicate denser material,

while blue is less dense.

With Naples and several

other communities in Italy

dangerously close to Mount

Vesuvius, scientists are

using muography to try

to predict the volcano’s

hazards.

Showa

Minamidake

muons.indd 26muons.indd 26 4/6/22 9:15 AM4/6/22 9:15 AM