On 22nd April, 2015, the Calbuco
volcano in Southern Chile erupted
without warning, sending a cloud of ash
12 miles into the sky.
Shortly afterwards a second eruption
fired more ash and volcanic rocks high
into the air.
The ash cloud has since drifted
eastwards towards Argentina,
disrupting airlines, which cannot fly
through dense ash. Where the ash has fallen on the ground, it has blocked roads, caused roofs to collapse
and covered grasslands so that farm animals have been threatened with starvation.
Chile is one of the main hotspots in the world for earthquakes and volcanos, as two tectonic plates (the
Nazca and South American) collide just west of the Chilean coastline. Uplift has built the nearby Andes
mountains, which rise to over 22,000 feet, and there are over 50 active volcanos in the country. Chile has
also suffered several of the strongest earthquakes ever recorded, including the strongest ever – a 9.5
quake in 1960 which created a tsunami with waves 25 metres high. In 2010 an 8.8 quake hit Southern
Chile, the sixth greatest earthquake ever recorded, which caused another tsunami along the Pacific coast.
On 24th April, 2015, an earthquake measuring 7.8
on the Richter scale struck the Himalayan
country of Nepal. The epicentre of the quake (the
point on the Earth’s surface straight above the
focus of the earthquake) was between the capital
Kathmandu and the tourist centre Pokhara.
Nepal is a hotspot for seismic activity, as the Indian tectonic plate to the south
(part of the Earth’s crust) collides with the Eurasian plate to the north. The uplift
caused by this destructive plate boundary has built the Himalayas, the highest
mountain range in the world. They are still growing! Although the people of the
Himalayas are used to earthquakes, this is the worst they have suffered for more
than eighty years…
Tremors from the quake were felt as far away as Delhi in India. These seismic
vibrations (including many aftershocks) collapsed many buildings – Nepal is not a
rich country, and few buildings were designed to withstand a quake. Most of the
people who have died have been crushed in or near to buildings. Tremors also
caused a major avalanche on Mount Everest, and at least seventeen people there have died.
Further problems have been caused by the disruption which the earthquake has caused to transport and
to medical facilities. Kathmandu airport was severely struck, making it difficult for people to escape and
for aid to be flown in. Roads have been blocked by debris, hampering the work of the emergency
services. Police are digging with pickaxes – and some people with their bare hands – because bulldozers
cannot get through the narrow, ruined streets. Mobile phone coverage (as in many disasters) has been
severely restricted as the networks lost masts and thousands of people tried to contact friends and relatives
all at once. This has made it difficult to contact remote places away from the main towns…
At the time of writing this (Sunday 26th), the death
toll was still uncertain and rising rapidly. From 100+
dead, it is now thought to be 1,900 or more. It is
highly likely that the death toll will have risen much
further by the time you read this.
Pictures: top left: a collapsed building in Kathmandu.
Poor countries (less developed countries or
LEDCs) cannot afford the high standards of building
which more developed countries (MEDCs) like
Japan or the U.S.A. have. This is why so many more
people are killed in earthquakes in poor regions.
Top right and middle left: the emergency services in many places struggle to cope as it is difficult to reach
the large number of buildings affected by the quake. Often rescuers have to manage as best they can…
Below left: survivors of the earthquake often choose to sleep out of doors, either because they have lost
their homes, or because they are afraid of aftershocks (smaller earthquakes which often follow big ones).
Aftershocks can collapse buildings weakened by the first quake.
Below right: aid is beginning to arrive
from other countries around the world. The boxes in the picture are from Sri Lanka and have been flown
into Kathmandu airport. It is still difficult to get them to everywhere they are needed. Pakistan has sent an
emergency mobile hospital: many countries have sent medical supplies. Some countries are sending
teams with sniffer dogs, trained to find people buried in rubble. Once people have been rescued, Nepal will
need much help to rebuild its ruined capital city.
There is much work to do outside the cities: many
towns and villages are still cut off from help by
landslides which were triggered by the earthquake.
On Mount Everest, helicopters are beginning to
evacuate people injured and trapped by the avalanche
which killed at least 17 climbers at Base Camp. This is
already the greatest disaster on the mountain – and
there are still people trapped higher up the mountain.
One climber has already texted for help – there is no
way down to Base Camp any more…