Phys.org has a story about sea level over the last 540 million years.  Sea level change is a hot topic in Earth Science.  As the Earth warms, the level will increase due to melted ice and the expansion of water.  A new paper “Phanerozoic orbital-scale glacio-eustatic variability” in the journal Earth and Planetary Science Letters, details the change over the last 540 million years.  Looking deep into the history of the Earth, researchers can better understand the changes in the future.

“Taking these rapid sea level variations into account is important for understanding the structure of the subsurface, and the applications to green energy resources,” says Dr. Douwe van der Meer, guest researcher at Utrecht University and lead author of the study.

How high or low sea level is depends largely on two things: plate tectonics determine how deep the bathtub is between continents, and the amount of land ice determines how much water is in that bathtub.

“In time steps of about a million years, you can derive an average sea level for as far back as there are fossils, about 540 million years,” says Dr. Van der Meer. “That varied by as much as 200 meters. We suspected that sea level could go up and down enormously in much shorter periods as well, but there is not enough data to make those shorter time steps.”