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WAKING THE GIANT: how a changing climate
triggers earthquakes, tsunamis and volcanoes
Bill McGuire
Professor of Geophysical & Climate Hazards UCL
UGLY SCIENTISTS…..
José Mourinho. Chelsea FC Manager
BBC Online. February 20th 2005
…..AND MAD ONES
 Plenty of evidence from the past
 Tiny changes in environment
capable of triggering hazardous
geological phenomena
 Climate change is already
starting to affect the solid Earth
 Modelling suggests more to come
PROXIMATE VERSUS ULTIMATE CAUSE
 A changing climate CAN NOT
cause earthquakes, volcanic
eruptions or landslides that
would not have happened
anyway
 Climate change has potential to
act as a trigger or proximate
cause
 Bring forward occurrence of a
quake or eruption
 Potential influencer or
modulator rather than ultimate
cause
 The power of the ‘pressure of a
handshake’
FINDING OUT MORE
THE TALK
1. Looking back
3. Looking ahead
2. Where are we now?
4. The last straw
ICEHOUSE TO GREENHOUSE
IT’S ALL ABOUT WATER
 Temperatures up 6°C or so
 Cold, arid climate replaced
by warmer, wetter,
conditions
 52 million cubic kilometres
of water shifted from ice
sheets into ocean basins
 2 -3km thick ice sheets
melted at high latitudes
 130m load added to ocean
basins
 Mass change lengthened
day by 4 seconds
WHAT GOES DOWN MUST COME UP
Active fault
Depressed
crust
Rising magma
BOUNCING BACK
Going up
Going
down
EARTHSHOCK!
Basel 1356
Stuoragurra Fault
New Madrid 1811-12
Pärvie Fault
TSUNAMI UK
The great
Storegga landslide
VOLCANO STORM
52 million cubic km
of water
Continental
ice sheets
Ocean
basins
WATER…WATER!
Action zone
GLOBAL RESPONSE
High Andes (Chile)
Massif Central (France)
Vesuvius
San Andreas (California)
WHERE ARE WE NOW?
Kolka (Russia) 2002
Bagley Ice Field
Bering glacier
Mount Steller
A CLIMATE TRIGGER FOR THE NEPAL QUAKES?
 NEWSWEEK cover story
 Climate change did not
cause the Nepal quake
BUT……
 Recent research finds
monsoon water loading in
Gangetic Plain modulates
earthquake occurrence in
Himalayas
 Results in significantly
more earthquakes Dec Feb
GOING FORWARD
 Will we see a rise in numbers
of quakes, eruptions and
landslides worldwide?
 Will we be able to allocate a
particular geological event to
climate change?
 Are there places where we
may see an unequivocal
geological response to
climate change?
 Are we able to identify
especially susceptible
seismic and volcanic
threats?
WAKING GIANT?
Iceland uplift
Vatnajökull Ice Cap
Öraefajökull
Bardabunga
ICELAND
REJUVENATED
FURTHER AFIELD
Etna
Rainier
Coastal volcanoes
Snow-capped volcanoes
Sollipulli
Casita
Tropical volcanoes
A SHAKIER FUTURE?
MEGAFLOOD
More of this? Haiti 2010
Less of this? Japan 2011
Imja Tsho Nepal
THE LAST STRAW
Pavlof: sea level
Taiwan tremors: typhoons
Montserrat eruptions: rainfall
Japanese earthquakes: snow
NICE DAY FOR AN ERUPTION
More eruptions occur from November to March
Attributed to seasonal redistributions of water mass
To conclude…..
 The climate and the solid Earth are intimately connected
 Role for CC in promoting hazardous geological events is well
established
 ACC already triggering earthquakes and landslides in some regions
 Modelling suggests future response will be more widespread
 Most at risk are ‘critically poised’ systems
 Geologically ‘quiet’ regions may become active
 Seismic rejuvenation of Greenland
 Other regions will become more active
 Increase in major landslides in high-mountain terrain
 Jury out on whether there will be a discernible/statistically significance
rise in the number of earthquakes, eruptions and landslides