Subject: 5 February Report from Bill Lettis in India

The following is a field report from Bill Lettis , a member of the EERI investigation team, sent to Susan Tubessing of EERI 5 Feb 2001, and distributed by Bill John McRaney to SCEC members.

Dear Susan

I must rush. It is impossible to get connections on e-mail, so I have dialed
long distance, and am sending this online.

We have been here for two full days. A quick update. Please send this
update to the extended e-mail list on my original e-mails (i.e., JP Bardet,
Wesnousky, Rockwell, Bray, etc. just to keep everyone informed.

In no particular order, just brain dump at 2 AM.

Everyone is working hard and doing great. We have a good team.

First Day - hectic coordination. No real access, fuel problem for vehicles
in the field (but not really, so all is okay), etc, etc. I think sometimes
that I am gulliBill.

No food or water readily available like Turkey or Taiwan. EVERYONE should
bring full supply of dried food, nuts, etc to stay in the field until
conditions improve. Need supply of bottled water everyday - daytime temps in
the 80s, dry. No wind though. Bring tent, sleeping bag, and other camp gear
desired, if you want to spend time in the field. Hotels may be available, we
are checking in Ghandi Dam, but most places are damaged. We will see.
Camping may be available with the United Nations near Bhuj, but not sure.
Indian Military not much help so far. We will know tomorrow if we can stay
at the military base.

Money - bring cash if you go in the field. Hotels in Ahmedabad take visa.
Flying, cars etc want cash.

Flying is very expensive. $550/hour for fixed wing and $1000 to 1500 /hour
for helicopter. Need to fly in from Ahmedabad so time is minimum of 6 hours
to give two hours of reconn. Flying conditions not good. Flight paths
heavily restricted and elevation mandatory over 3000 feet to avoid helicopter
traffic. In other words - lousy air recon at this time. We NEED to get the
Governement of India to help get permission for better recon- we will work on
this over next few days. A helicopter MAY be available in Bhuj airport, thus
we save 4 hours of ferry time from Ahmedabad. We can probably arrange this,
I spoke to pilot directly. Probably plan to spend 3 to 10 k for flying, if
you want to go.

Air recon results - Interesting:

We did not observe ANY evidence of surface fault rupture. Highly unusual
given the size of event and amount of probable slip. We did see about 1/2 km
of surface cracking in epicentral area, but this appears to be related to
liquefaction. We will visit this area in the field. However, due to flying
restrictions, we were not able to recon one of the main candidate faults in
the area. This fault is the eastern continuation of the Allah Bund fault and
is right en echelon to the Allah Bund (called the Island Belt Fault). We
will try to visit this fault in the field. It is close to the Pakistani
border, hence flying restrictions. Rockwell and Wesnousky - if you are
coming mainly to characterize surface fault rupture, you may want to wait.
It is interesting that no one has reported fault rupture, including local
people (valuable source usually), media, government, GSI geologists who have
been looking for one week now, and we did not see any from the air. This
strongly suggests that if any occurred, it is up north away from population
an the eastern exstension of the Allah Bund. We will see. ALSO, does anyone
have any preliminary interferometry data to help identify the deformation
field??? This will be a BIG help in doing future recon.

Lots of liquefaction. At least 500 km2 north of Bhuj on the Banni plains.
Maybe up to 1000 km2. Mostly sand blows, with lots of water - standing
shallow lakes now in many areas. A few lateral spreads, not many that we saw
from the air. We should definitely try to describe the lateral extent and
magnitude of liquefaction relative to epicenter and strong motion data -
great possible data set.

Kandla Port - did not look too bad from the air. Road to port definitely
damaged from what appears to be lateral spreads. No significant apparent
damage observed from air. We are visiting port in next two days.

Stable Continental Shield?? I would say definitely not. This area appears
to be an actively growing fold and thrust belt. Lots of anticlines with
apparent Quaternary activity. Folds are assymmetric, north vergent. A few
possible fault scarps, but most scarps appear to be related to fold limbs.
Definitely active folds, however. Individualo folds are on the order of 50
km long, in fold trends that are up to 200 km long. Folds are en echelon in
each trend suggesting lateral component. One fold appears to be deforming
the modern mud flats along the coast east of Kandla. Definitely active.
Rate of shortening?? No idea yet. Many rivers and washes draining the folds
have impressive flights of fluvial terraces, suggesting fairly rapid uplift
of folds. Great future Ph.D study - Tectonic Geomorph of the region -
unfortuantely, no air photos are availble to map with.

Computers/ safety/ etc. Everything is okay. Not really a problem as far as
I can tell, except e-mail connections are a bitch.

Tapper Dam and Ghangi Dam. These are cities, NOT dams. When someone says
that these are damaged, they mean the cities. (Dam mean town or city in
Hindi).

Embankment dams. We observed at least four (one large and three small)
embankment dams that experienced toe failures at upstream side., one dam
nearly failed it appears.

Tank farms near Kandla. Tanks appeared to be okay, No major tank spills,
but someone needs to check more carefully. However, at least two large oil
spills are present, apparently from pipe (?) failures. We are checking this
out.

Salt ponds. Lots of salt ponds are around, especially east of Bhuj and south
along the coast. The salt ponds east of Bhuj (east of epicenter) experienced
both dike failures and seich failures or breaches. Can this help with
long-period ground motione stimates??

Damage. Ahmedabad survived very well, despite the many isolated building
collapses. We have all the buildings identified and they are easily mapped.
We should compare the distribution of buildings damaged to geotechical
conditions to try to see what controls threir failure (probably just some
spotty construction we suspect). No real "pattern" discernible yet (building
type, spatial distribution, geologic condition, etc).

Damage continued. Bhuj heavily damaged, kind of like Golchuk, but far more
single story houses. Dozens of small communities north and east of Bhuj
(1000 to 5000 people), totally destroyed (80 to 100!!%) building collapse of
all types. This is an interesting story in of itself, and not getting much
attention. LOTS of local people lost in the relief effort because towns are
too small to get attention. I don't know, but this might be an issue worth
discussing (Krishna will look into this).

Ancient wall of Bhuj (about 400 yrs??) heavily damaged.

Ancient cities. This area appears to have been widely settled BC sometime,
but abandoned at some point. This could be a great story if someone looks
into it. Lots of possible reasons for abandonment, but obvious one is
earthquake.

Ancient Rivers. For some reason, several major tributaries to the Indus
River have vanished or shifted course. This apparently is because of uplift
and active growth of the fold and thrust belt. It also helps to explain why
early people abandoned the area. I do not think that climatic change caused
the change in river course or disappearance of these rivers that are
described in early history documents.

Liquefaction along coast. Some of the best offshore liquefaction that I have
ever seen. Widespread offshore liquefaction was visible from the air south
east of Kandla Port. Very interesting. I don't know scientific value if any.

Team Assignments. Two teams of four have gone to field today, and will stay
wherever they find shelter for the next two to three days. (Geotech team
with Sudhir Jain and Umesh Dayal, and Industrial facilities and Lifelines
team with Gupta and Don B.) Structures team - Rakesh Goel, Murty, etc are
working for next day or so on building damage in Ahmedabad. Geology team
(lettis, hengesh, narula, chaubey) will go to field for next two to three
days.

Things are beginning to smooth out and logistics are improving. This is
really a great earthquake with lots of things to document.

Sorry for the quick note, but I have been on line to US for over one hour and
need to get off. I will try again in two days.

Bill Lettis