The Potsdam Gravity Potato
Explanation:
Why do some places on Earth have higher gravity than others?
Sometimes the reason is unknown.
To help better understand the
Earth's surface, sensitive measurments by the orbiting satellites
GRACE and
CHAMP
were used to create a map of Earth's
gravitational field.
Since a center for studying this data is in
Potsdam,
Germany, and since the result
makes the Earth look somewhat like a potato, the resulting geoid has been referred
to as the Potsdam Gravity Potato.
High areas on
this
map, colored red, indicate areas where gravity is
slightly stronger than usual, while in blue areas gravity is
slightly weaker.
Many bumps and valleys on the Potsdam Gravity Potato can be
attributed to surface features, such as the
North
Mid-Atlantic Ridge and the
Himalayan Mountains,
but others cannot, and so might relate to unusually
high or low sub-surface densities.
Maps
like this also help calibrate changes in the
Earth's surface including
variable ocean currents and the
melting of glaciers.
The above map was made in 2005, but more recent and more sensitive
gravity maps
of Earth was produced in
2011.
Now Available:
APOD 2015 Wall Calendars
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
