Expert: John J. Shea - 2/22/2005

Question
hi,
I don't know if this falls under your domain or not, but the other day I saw on the news about how the tsunami that hit asia had uncovered some ruins belonging to an ancient city in India. My question is, how is it that cities are built on  top of other cities? I understand examples such as Pompeii, but what other factors are there?

thank-you very much!

Elizabeth Woyce

Answer
Hi Elizabeth
Sorry if this is a repeat message.  I thought I answered it, but found it listed as "pending" when I logged on to answer another question.
Cities tend to be built in places that have access to fresh water, nearby arable land and easy transportation/communication routes.  Each of these can fail from time to time, leading to a city being abandoned, or its population reduced.  After  some time, the problem that led to abandonment/population reduction can disappear and the same place become an optimal place for a city to be begun again.  This is a fairly common thing in the past.  In some parts of the Near East and South Asia, there are huge mounds built up over successive occupations.
The ruins exposed by the tsunami were probably abandoned, then covered by silts and clays from river flooding.  The tsunami created severe erosion, exposing their remains.
I hope this answers your question.
Cheers,
John Shea