In news: According to new research, glacial melting due to global warming has probably been altering Earth’s poles since at least the 1990s.
- The study is published in Geophysical Research Letters of the American Geophysical Union (AGU).
- The Earth’s spin around the invisible axis running through the center of Earth’s mass is dependent on the distribution of weight around the globe and it shifts just like a spinning top.
- The axis Earth spins around is always moving and the way water is distributed on Earth’s surface is one factor that drives the drift.
- The study noted that the average drift speed between 1995 and 2020 increased about 17 times from the average speed between 1981 and 1995.
- Melting glaciers redistributed enough water to cause the direction of polar wander to turn and accelerate eastward during the mid-1990s.
- The researchers found that the contributions of water loss from the polar regions is the main driver of polar drift, with contributions from water loss in nonpolar regions, causing the eastward change in polar drift.
- While this change is not expected to affect daily life, it can change the length of the day by a few milliseconds, experts say.
- The calculations were based on satellite data from NASA’s Gravity Recovery and Climate Experiment (GRACE) mission as well as estimates of glacier loss and groundwater pumping going back to the 1980s.
- While ice melting is the major factor behind increased polar motion, groundwater depletion also adds to the phenomenon.
- The Gravity Recovery and Climate Experiment (GRACE) was a joint mission of NASA and the German Aerospace Center (DLR).
- Twin satellites took detailed measurements of Earth’s gravity field anomalies from its launch in March 2002 to the end of its science mission in October 2017.
- Data from the GRACE satellites is an important tool for studying Earth’s ocean, geology, and climate.
- The Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) is a continuation of the mission on near-identical hardware, launched in May 2018.