RSS Feeds

Email a Friend Printer Friendly

Geophysical Research Letters European Highlights - 1 August 2001

July 16, 2001

Highlights

4. Deep water has many sources

Hellmer and Beckmann ["The Southern Ocean: A Ventilation
Contributor with Multiple Sources"] use a coupled ocean/ice-shelf
model to determine the location and rate of Antarctic Bottom
Water (AABW) formation. Their results suggest that the Atlantic
and Indian-Pacific are equal contributors but produce bottom
waters of different density. As in observations and analyses, the
model calculates that the southern oceans have multiple bottom
water sources producing dense AABW at a rate of approximately
10 Sverdrup [unit used to measure the volume transport of ocean
currents], the Atlantic being the dominant source. The authors
report that the southern and northern hemisphere sources are equal
contributors to the ventilation of the deep world ocean.

8. Large earthquakes also follow the law

For many years, there has been a debate about why large
earthquakes do not appear to fit the scaling laws for smaller
earthquakes. This observation would seem to imply that the
physics of large earthquakes is somehow fundamentally
different from that of smaller events. Shaw and Scholz ["Slip-
length scaling in large earthquakes: Observations and theory and
implications for earthquake physics"] bring together recently
compiled observations of large aspect ratio earthquakes and a new
3-D dynamic earthquake model to show that the larger earthquakes
do, in fact, follow the same scaling laws as the smaller events.
These new results generate renewed confidence in using
observations of more common smaller earthquakes to predict the
effects of the rare and damaging great earthquakes.


American Geophysical Union (AGU)