The fall meeting of the American Geophysical Union (AGU) in San Franci
sco last month was bumped to the Moscone Center while the Civic Audito
rium, its venue in past years, was being reinforced against earthquake
s. And that may have been fitting, given the meeting's focus on sudden
events in Earth history: the first moments of fault rupture, repeated
outbursts of icebergs during the last ice age, and a shift in the sea
sons in the middle of this century.