Spinning faster

Human endeavours like the building
of dams are now being held responsible for the planet spinning a wee bit
faster. Benjamin Chao, a geophysicistat NASA's Goddard Space Flight
Center in Greenbelt, Maryland, US,
says that the days are shortening by
about O;2millionthsofa second per
year. Chao's observations are based
on a study of artificial reservoirs like
dams, and how this redistribution of
water is affecting the earth's spin. As
most dams are situated in the
NQrthern Hemisphere, there has
been a net shift in the water closer to
the earth's axis and away from the
equator, resulting in faster spins
(DiScover, Vol17 , No 4).