The continents of earth are helping slow down sea level rise, a new study shows. Melting glaciers and ice sheets are causing sea levels to change around the world, but the continents are actually absorbing a lot of this excess water.
NASA’s Jet Propulsion Laboratory conducted a study to find out how much continents absorb. Two orbiting satellites showed that the continents slow the rise of sea levels by nearly 20% every year, which equates to about 1 millimeter. The satellites detected changes in Earth’s gravitational pull, which is affected by mass. Water has a lot of mass and is the only thing heavy and mobile enough to change Earth’s gravity.
Nearly 6 trillion tons of snow, ground water, surface water and moisture from the soil are cycled through Earth every year. The continents are in charge of part of the water cycle, which affects how much water is eventually released back into the oceans.
The overall volume of water in the Earth’s seas have increased as glaciers and other ice sheets have started to melt. Scientists averaged the rate of sea level rise compared to how much water was melting and found that the levels weren’t rising as fast as they thought. They researched the phenomena further and found that the continents are picking up the slack when it comes to water absorption.
The satellites in use for the project can detect where there are gravitational anomalies because of things like California’s drought or a big flood in Southeast Asia. The satellite data has allowed NASA to create a map which shows where there have been water increases and decreases around the world in recent months and years.
Scientists know that the continents can’t hold all the water being released into the ocean by glaciers and ice sheets. Ultimately this still comes down to changing the environmental habits of humans by limiting our carbon emissions and lessening our negative impact on the environment.
Reager, J. T., Gardner, A. S., Famiglietti, J. S., Wiese, D. N., Eicker, A., & Lo, M. H. (2016). A decade of sea level rise slowed by climate-driven hydrology. Science, 351(6274), 699-703.
Thirsty continents are slowing down expected sea level rise, scientists say. LA Times, February 15, 2016.