By Marcia-Ruth Ndege ’21

Over the past few decades, global climate change has become a widely debated issue. Its believability, however, is no longer relevant as we are living through its effects across the globe; whether it be through melting glaciers in the Arctic, droughts and wildfires in California, or decreased rainfall in Ethiopia, the effects of climate change are prominent and devastating. A new investigation into this matter has uncovered an unexpected consequence of rising sea levels due to climate change: a sinking ocean floor.

In March of 2002, NASA and the German Aerospace Center launched the Gravity Recovery And Climate Experiment (GRACE) satellite mission; two satellites spent seventeen years procuring detailed measurements of earth’s gravitational anomalies before returning to earth in October of 2017. The data collected from the mission allowed scientists and researchers to compute global mass distribution and consequent ocean floor deformation. Albeit solid, the earth’s crust has elastic properties that allow it to reconfigure its shape in response to seismic waves and the distribution of the water on top of it. Seismic waves are waves of energy caused by the sudden breaking of rock within the earth or an explosion. As the amount of water on earth’s surface increases, the crust’s elasticity gives way. With this new data in mind, scientists have concluded that the estimates of rising sea levels have been incorrect since 1993, underestimating the expected increase by around 8 percent.

The issue of rising sea levels is considered urgent as it has catastrophic consequences, particularly on coastal habitats. Rising levels and the sinking ocean floor can submerge resident islands, causing migration of indigenous people, disruption of ecosystems, species extinction, and cause even more consequences that we are just now discovering to be true.

References:

1. T. Frederickse, R. Riva, M. King, Ocean Bottom Deformation Due To Present-Day Mass Redistribution and Its Impact on Sea Level Observations. Geophysical Research Letters. (2017) doi: 10.1002/2017GL075419
2. Image retrieved from: https://pixabay.com/p-2254711/?no_redirect