latest stories:  Warm Currents Threaten to Expand Antarctic
Melting  Warm ocean waters are carving away the undersides of
Antarctica's ice shelves, which will speed their melting Edge of
the Ross Ice Shelf as seen by the NATHANIEL B. PALMER. 1997
December.  flickr/NOAA Photo Library  Another section of the
vast Antarctic ice sheet is threatened by warm ocean waters,
scientists reported yesterday.  Researchers have watched as
warm, deep currents have carved away at the underside of ice
shelves on the western Antarctic coast, accelerating ice loss by
eroding the floating ice tongues that help slow glaciers' flow
to the sea.  Now a pair of new studies suggest that, by the end
of the century, the same process could begin thawing a portion
of the vast Antarctic ice sheet that researchers considered to
be relatively stable.  The Filchner-Ronne Ice Shelf covers more
than 174,000 square miles in the Weddell Sea on the eastern side
of the Antarctica Peninsula. The new research suggests that
region, which has not exper