Re: what caused the sea level rise?

The global cycles of relative changes in sea level was published in 1977
by Vail et al., where three orders of cycles were recognized, with
duration of
- 200-300 million years
- 10-80 million years
- 1-10 million years
These cycles were characterized by slow increases in relative sea level,
followed by periods of rapid falls, on timescales of less than 1 million
year. The magnitude of these variations is about 1 cm/1000 years, and
it can be caused mainly by two factors:

- glacial fluctuations in sealevel, that can cause worldwide changes;
- horizontal stresses in the lithospheric plates (order of some kbar).

To understand the horizontal stresses, remember that if you have
a thin rubber, and compresses it horizontally, it will suffer
deformation; the same basic idea applies to the plates, although
the forces necessary to bend it are much greater.

So, these two factors act in the sealevel rise, and in some
periods, where there's no evidence of glacial fluctuations, the
stresses could be responsible this variation.

Eder C. Molina
Institute of Astronomy and Geophysics
University of Sao Paulo
BRAZIL
eder@iag.usp.br