- A huge chunk of the Cumbre Vieja volcano, on the Canary
Island of La Palma, is on the move. In 1949, this mass of rock - perhaps
as large as the Isle of Man - dropped 4 metres seawards and stopped.
-
- Monitoring in the mid-90s suggested that it was continuing
to creep downslope, though only at a centimetre or so a year. At some time,
however, and we don't have a clue when, the landslide will plunge into
the north Atlantic, generating gigantic tsunamis - sea waves likely to
be 50 metres high or more - that will devastate the Caribbean and eastern
United States, as well as the Canaries themselves, southern Europe and
western Africa.
-
- Without evacuation, the destruction will end the lives
of tens of millions and bring the global economy to its knees overnight.
-
- You might expect that this landslide would be one of
the most closely studied on the planet, but that would be far off the mark.
In reality, nobody is monitoring the situation, and the island's authorities
are reportedly allowing new building developments to go ahead.
-
- Why does nobody care? In the second half of the 20th
century we planned for the nuclear winter that would follow an atomic exchange,
but we now give little thought to the similar conditions that would certainly
prevail after an asteroid impact or volcanic super-eruption.
-
- Even now, it is all the rage to hold nanotechnology and
exotic physics experiments gone wrong as harbingers of doom, while regarding
the certain threat of natural catastrophes with either a snort of disdain
or a bellow of laughter. Despite existing, and indeed thriving, on planet
Earth purely as a consequence of nature's benign consent, it seems that
humanity has a blind spot when it comes to addressing what will happen
when that consent is withdrawn.
-
- The Earth has been around for a very long time - something
approaching 4.6 billion years. Business as usual involves serious pounding
by asteroids and comets, the rending of the crust by gigantic outpourings
of lava and the battering of the ocean-basin margins by enormous waves
climbing to heights in excess of 100 metres.
-
- In the blink of an eye that humans have been recording
their experiences, it is hardly surprising that we have yet to witness
one of these global geophysical events (or gee-gees, as they are known).
But they are not going to stop happening.
-
- In any single year it is extremely unlikely that any
of us will succumb to a volcanic super-eruption or a direct hit from an
asteroid, both events that have the potential to kill about one in six
of the world's population.
-
- A collision with an asteroid large enough to cause global
mayhem happens only once every hundred millennia, while a gigantic volcanic
blast occurs perhaps every 50,000 years. They are, however, certain to
happen. Both trigger rapid and severe global cooling that, apart from the
absence of radiation, is in every way comparable to the nuclear winter
that would follow an all-out exchange of atomic hardware.
-
- Following the last super-eruption - 73,500 years ago,
at Toba in Indonesia - the entire planet may have been plunged into darkness
for several years, with bitter cold destroying plant life and wiping out
most of our predecessors - leaving behind just a few thousand from whom
all of us are descended.
-
- How would Britain cope in such a situation today, with
our crops devastated and 60 million people to feed for years?
-
- The easy option is to lie back and relax, secure in the
knowledge that, statistically, we probably won't be around when the next
gee-gee strikes. Others will be, however - and if not our children or grandchildren,
then certainly their descendants. And if they hold to the current line
of thinking, they will be no better prepared then than we are.
-
- But what can we do? Worrying ourselves to sleep every
night or launching a global war on nature is clearly not the answer. We
can, however, begin a serious horizon-scanning exercise, looking further
than the next election or international trade treaty to the global catastrophes
we must face at some point in the future.
-
- To some extent, this has already started, with scientists
worldwide making a concerted effort to spot all the Earth-threatening asteroids
in the next few decades.
-
- But we have barely scratched the surface in trying to
understand and assess the threat posed by other potential gee-gees. Of
the 3,000 or so active and potentially active volcanoes, for example, we
are monitoring just a few hundred.
-
- A volcano in the remote southern Andes could have been
building towards a super-eruption for many decades, but we would know nothing
about it until it blew itself apart.
-
- The situation on La Palma demonstrates that even when
we are aware of a potentially devastating threat, we seem to prefer to
ignore it in the hope that it will mysteriously disappear. Clearly, however,
it won't, and it is about time that we sat up and paid attention to what
nature can and will do.
-
- A wild-haired physicist wearing odd socks could be cooking
up a black hole in his laboratory this very minute, but then again he or
she almost certainly isn't.
-
- Meanwhile, lurking somewhere out in space or closeted
beneath the Earth's crust, there is a large rock or a heaving mass of magma
with your name on it - or if not yours, then certainly one of your descendants.
-
- - Bill McGuire is the director of the Benfield Hazard
Research Centre at University College London. His book, A Guide to the
End of the World: Everything You Never Wanted to Know, is published by
OUP. w.mcguire@ucl.ac.uk
-
- Guardian Unlimited © Guardian Newspapers Limited
2003
-
- http://www.guardian.co.uk/naturaldisasters/story/0,7369,1068213,00.html
|
