New Scientist - USA (2020-04-25)

(Antfer) #1
12 | New Scientist | 25 April 2020

THE huge eruption of Kilauea
volcano on Hawaii in 2018 was
triggered by extremely heavy
rains, according to a new
analysis. The water caused
pressure to build up deep inside
the volcano, fracturing the rock
and allowing hot magma to rise.
The finding bolsters the idea
that rainfall can affect volcanoes
and thus that climate change
could lead to more eruptions.
Kilauea began erupting at
the end of April 2018, when the
floor of its lava lake collapsed.
The volcano crumbled and
huge volumes of magma flowed
over the landscape, eventually
reaching the coast. The eruption
continued for months.
Why it happened was unclear.
The volcano didn’t expand in
the weeks before, which would
have indicated new magma
entering from below. Instead,
the upper rocks that keep the
magma trapped must have been
weakened, allowing it to escape.
Jamie Farquharson and Falk
Amelung at the University of
Miami in Florida noticed that
Hawaii had unusually heavy rain
in early 2018. On 14 to 15 April,

1.26 metres of rain fell within
24 hours – a US record. In the first
three months of 2018, Kilauea
had 2.25 metres of rain, when it
would normally get 0.9 metres.
Previous research suggests
that passing storms can cause
small explosions when they
interact with unstable material
on the surface of a volcano,
says Farquharson. For instance,
the Soufrière Hills volcano on
Montserrat in the Caribbean
erupts more after heavy rain.
“Our study goes further,” says
Farquharson. He and Amelung
used rainfall data to calculate
how much pressure built up
inside the volcano as a result
of increased groundwater,
finding that, in early 2018,

the pressure was at its
highest  for almost 50 years.
They suggest that pressure
fractured the rock, letting
magma rise and erupt (Nature,
DOI: 10.1038/s41586-020-2172-5).

This is backed by historical
evidence. The pair found that
about 60 per cent of Kilauea’s
reported eruptions since 1790
began during the five-month
rainy season. Notably, a
spectacular eruption in May
1924 was preceded by extreme
rain. Furthermore, magma
seems to be more likely to ooze
into the volcano from below
when internal pressure is high.
“It’s definitely a possibility of
explaining this eruption,” says
Carolina Pagli at the University
of Pisa in Italy. She says previous
claims of “volcano weather”
haven’t stood up to scrutiny,
but here the historical data
is “particularly convincing”.
The finding could help
improve eruption warning
systems for Kilauea, says Pagli.
“I am not at all surprised,”
says Bill McGuire at University
College London, who has long
argued that climate change
will trigger more volcanic
eruptions, earthquakes and
tsunamis as melting ice sheets
and extreme rainstorms alter
the pressures that control
geological phenomena.
“The fact that tropical
cyclones are already getting
much wetter, and will become
more so, could mean that
they will provide increasingly
effective triggers for eruptions
at tropical volcanoes that
are primed and ready to go,”
says McGuire.
Farquharson says this may
be the case, but every volcano is
unique. “The study is concerned
solely with Kilauea volcano and
cannot necessarily be applied
more generally without further
detailed research.” ❚

THE next big thing in fashion
may be vibrating clothes that
elicit the sensations of clouds,
water and rocks on the skin.
Ana Tajadura-Jiménez at
Charles III University of Madrid
in Spain and her colleagues sewed
tiny vibrating motors – each
10 millimetres across and
3 millimetres thick – into three
materials: jersey fabric, fluffy
polyester and smooth polyester.
They programmed the motors
to vibrate in specific patterns by
connecting them via wires to a
pocket-sized control board and
battery pack, then placed the
materials on the arms, backs
or hands of 19 people.
The volunteers were asked to
describe the resulting sensations
using a number of terms.

The researchers placed these
responses into one of three
categories: cloud, rock or water.
For instance, if someone described
the feeling on the skin as soft, cosy
and warm, their response went in
the cloud category (Frontiers in
Robotics and AI, doi. org/dr8n).
Certain patterns tended to
produce similar sensations:
for example, expanding circles
prompted responses that fell into
the cloud category. The type of
material also had an effect, with
vibrations passing through fluffy
polyester feeling more “watery”
and those travelling through
smooth polyester more “rocky”.
The team also created a dress
that gives rise to similar sensations,
as part of work to design clothes
that can be “experienced”, says
Tajadura-Jiménez. “Clothes have
so much potential for caring for
us,” she says. ❚

Kilauea volcano
on Hawaii heavily
erupted in 2018

Technology Geology

Alice Klein Michael Marshall

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News


“ Expanding circles of
vibration led to a sensation
that was described in
cloud-like terms”


Volcanic eruption caused


by torrential rain


Vibrating clothes
evoke the feeling
of wearing a cloud

2.25m
of rain fell on Kilauea volcano
in first three months of 2018
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