Earthquake Presentation

 The underlying geology of California causes most of the problems.  Most of the areas are built on reclaimed soft soil.  The main problem comes around when the quake occurs. The hard rock provides resistance to the stock waves and they are impeded and reduced in intensity.  The clays and soft soils magnify the waves’ power and can cause them to behave in various ways.  Buildings can simply sink, in fact, under their own weight.  The acceleration of the 1989 earthquake was 4*6g but it was propagated to 16*6 at the surface by the clay soils.

 The region in which the earthquake occurred is part of a broad seismic area, which stretches from Turkey to the Arabian Sea.  Here, the Arabian landmass is slowly colliding with the Eurasian plate.  The earthquake occurred along a small thrust fault, directly under Spitak.  During the earthquake, the northeast – facing side of the Spitak section rode up and over the southwest – facing side.  The main shock occurred near the intersection between Alavar fault and the Pambak – Sevan fault.

 In Armenia people were mostly vulnerable, that’s why they suffered so.  Most of the population lives in a high – risk environment, because they cannot afford something better and safer.  Land quality is poor  Lack of building regulations.  The majority of the people in Armenia cannot afford to live in big houses. They are not very expensive but even people who can afford to live in them, are also under high risk because the quality of the houses is cheap, and therefore they collapse easily.  Urbanisation, has also forced all the people to move to the city which increases the risk.

 In San Francisco, the number of people that died was much more smaller.  This shows that vulnerability was lower.  Using cutting edge technology, the people of San Francisco have predicted the earthquake and because San Francisco is an MEDC, they had been able to prepare fully.  Another crucial fact, is that infrastructure in San Francisco is not at all cheap, poor, or bad.  Most of the buildings in the city, especially the high ones, are made to resist any dangerous natural hazard, as much as possible.

 No seismic structure analysis was carried out  Local power supplies were cut and the government emergency radio system had failed.  The earthquake was predicted  The areas that suffered were only the ones that were in a high – risk surrounding.

 Very poor infrastructure  There was extremely low winter temperatures.  Officials were not ready for a disaster of this scale.  The Soviet government let in foreign aid workers to help with the recovery.