In January 2006, I was lucky enough to be able to undertake a
reconnaissance visit to Azad and Jammu Kashmir, the areas affected by
the 8th October 2005 earthquake, which had a magnitude of 7.6.
Here I have tried to present some pictures providing an overview focussing
mainly on landslides triggered by this
event.Muzaffarabad
Muzaffarabad is the largest city in the earthquake-affected area.
It suffered extensively from building collapses, especially on the
higher river terraces, and a number of large landslides were triggered
close to the river.
Image 1: This is an image of
extensive shallow rock slope failures on the east side of the city.
In the foreground you can see some of the tents associated with the
relief operations in the city - this is an army camp.
Image 2: This was a good quality
hotel in Muzaffarabad. Unfortunately it collapsed somewhat
catastrophically and will now need to be demolished. The woman in
the foreground was scavenging wood from the site, probably to burn to
keep warm.
Landslides south of Muzaffarabad
Image 3: Landslides also occurred
extensively in the sandstones of the Murree formation, as seen here.
Careful examination shows that in addition to the failed slopes there
are many others in various stages of progressive failure. On the
left side there is an area that has shown about 5 m of displacement,
whilst in the centre left there is an area with a 1 m wide arcuate
tension crack. The behaviour of these slopes during the monsoon
will be very interesting. Note the refugee village on the river
terrace - this would be threatened should a collapse occur in the dam at
the Hattian landslide
Image 4: Even though it was dry at the time
of my visit there were large numbers of landslides occurring throughout
the area, especially along the roads. This landslide was
continually active and required clearing several times per day.
Here the very brave bulldozer operators are pictured. Again, this
is going to become a major issue in the monsoon season.
Image 5: Across the whole of the affected
area there are vast numbers of tension cracks extending across the
slopes for hundreds of metres. Many of these clearly define
incipient landslides. Most were creeping at the time of my visit.
Again, one must fear for the behaviour of the slopes come the monsoon.
In this picture, an area of such cracks is shown. The house at the
front is on a graben structure. If you look closely you can see
that the house is being ripped in two even though it survived the
earthquake. Note also that it is still inhabited (there is washing
on the line). The house in the foreground is also likely to be
destroyed imminently. Despite this the owners are busy building a
new house as shown by the wooden frames. Unfortunately it is
inevitable that their new structure will be destroyed.
Image 6: In addition to the rock and soil
slopes there was also extensive collapse of the old uplifted terrace
edges. In many cases the towns are built on these terraces, and
often structures have been constructed that use the slope of the edge of
the terrace. Here such a structure is shown - unfortunately it
collapsed. Note also failure of the terrace edge on the other side
of the river (in the background). If you look carefully you will
also see where the foundation for a large concrete block that acted as
the stay for a small suspension bridge has also failed in the terrace.
Image 7: Across the whole of the area
affected by the earthquake shallow rockslides have been triggered on the
steeper slopes, especially where cutting has been undertaken as a result
of road construction. These slides are now causing major problems
for communication. Here, one of the small, high level roads has
been blocked by such a rockslide.
Image 8: The largest slide in the
earthquake zone is the Hattian rock avalanche. This is the large
slide identified on satellite imagery by, for example, Roger Bilham
(see: Hattian landslide).
This is valley-blocking landslide has an estimated volume of over 200
million m3 and a runout distance of about 2.5 km. It
has blocked the valley to a height of about 250 m. Two lakes are
forning at the time of writing. This view is from the side of the
landslide. Note that then slide has used a plunging syncline as
the shear surface. To the right of the picture can be seen a set
of boulders that spilled out of the slide area. Careful
examination of the montage means that the deposit can be seen in the
valley. The lakes would seem to represent a serious danger in the
(likely) event of rupture.
Image 9: A slightly better view of the
deposit from the Hattian landslide. Note the smaller of the two
lakes visible - this lake is close to breaching the deposit. The
large, much more dangerous lake is off-screen to the right. Note
also the clear evidence for large-scale post-deposition slope failures
in the deposit. It is assumed that these occurred shortly after
deposition.
Image 10: The sad remains of a ruined
school on the slopes adjacent to the Hattian landslide. This
building collapsed during the earthquake, killing 34 children.
These slopes, which are located above the larger lake at Hattian, are
massively sheared and cracked, posing a real threat of collapse come the
monsoon season. This is a dangerous situation in light of the lake
below.
Landslides north of Muzaffarabad
Image 11: This image shows the very large
rockslope failures in the river upstream of Muzaffarabad. These
failures were triggered by the earthquake - the fault runs at the base
of the slope in the middle distance and then through the terraces on the
right. The area of white water just visible is the location at
which the fault crosses the river. Note the dust in the air at the
top of the slope, caused by ongoing rockfall activity. These
slopes are clearly visible at the top right of the Space Imaging
satellite image - see:
Space Imaging.
Image 12: Near to Balakot there are very
large numbers of people living in tented villages. Unfortunately a
number of these are located an alluvial fans, such as this one.
Note the extensive new shallow rockslope failures in the catchment
areas, Many of the slopes here also show profound levels of
distress, with extensive, large head and laterial scarps. This
situation seems very dangerous in light of the forthcoming rainy season
- the conditions would seem ideal for debris flows (lots of new slope
failures and excess stores of sediment). Thus, these camps are in great
danger.
Image 13: Even in the dry season
keeping the roads open is a major challenge. These are falls along
one of the main roads close to Muzarrarabad. These falls occurred
overnight in dry weather. The impact on the local people is
profound. One fears for conditions come the rainy season.
Balakot
Image 14: The historic town of
Balakot has been effectively obliterated by the earthquake. This
image shows the historic centre of the town on a small hill. The
whole town has been demolished, with scarcely a building left standing.
Discussions continue in Pakistan as to whether rebuilding this town is
viable in its current location.
This page was compiled by Professor David Petley of the International
Landslide Centre at the University of Durham. Please contact me
for any further information or assistance. Postal address:
Professor David Petley, International Landslide Centre, Department of
Geography, Science Laboratories, Durham DH1 3LE, United Kingdom
Telephone: +44 191 334 1909
Fax: +44 191 334 1801
Email: d.n.petley@durham.ac.uk
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