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Mace & Crown | September 26, 2017

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Sea Level Rise Continues to Impact Old Dominion University Area

Sea Level Rise Continues to Impact Old Dominion University Area
Ben Maxie
Contributing Writer

Monarchs may have noticed that Norfolk floods almost every time there is significant rainfall. Subsequently, 49th St. is almost completely impassable at high tide after a storm. These problems are likely to worsen as the ocean continues to encroach on city streets.

By the year 2100, the water level could be around seven feet higher than today.

“Water lapping up on our shores runs over from storms, which will get worse,” Larry Atkinson, an eminent professor of oceanography at ODU, said.

As glaciers and ice sheets continue to shrink, the ice lost is dumped into the oceans. For example, Antarctica loses apartment building-sized icebergs on a regular basis, dumping around 310 cubic kilometers of land ice into the water per year.

Put simply, man-made climate change is an imbalance between the proportion of things that take in CO2 and produce oxygen– plants–and things that take in oxygen and produce CO2–animals.

“Internal combustion engines essentially added artificial heterotrophs (that make CO2),” Greg Cutter, an oceanographer at ODU, said. “It is the balance between hetero and autotrophs, that consume CO2 – plants, so now we are introducing more ‘heterotrophs’ without an equivalent amount of autotrophs.”

This effect is driving CO2 concentrations higher.

Atkinson said Norfolk land is also sinking. This is mostly “subsidence because of ground-water pumping from the deep aquifers,” he said. As water is pumped from pockets under ground, the land can sink to fill the space left behind.

A small amount of this effect is also from a process known as glacial isostatic adjustment.

“There was an ice sheet on Quebec and Ontario which is gone now. The land [around Norfolk] is still trying to compensate for this shift in weight,” Atkinson said. “Around one-third of the sea level rise is from this effect.”

Water also expands as it warms, raising the water level by thermal expansion. Water further expands because of a condition known as rising dynamic.

“There are high and low pressure areas in water, like air pressure,” Atkinson said. “There is a high area off the east coast, around three feet compared to Bermuda.”

As the climate changes, more sea level rise will stem from the Gulf Stream.

“Because the North Atlantic is warming and expanding and land ice in Antarctic and Greenland is melting, adding water to the ocean,” Atkinson said, “the Gulf Stream will slow.”

These conditions will not likely improve, and residents of low-lying areas like ODU must adapt. Low lying areas around the world, notably southern Bangladesh, are relocating people away from the rising water. This is a point of active discussion in the Hampton Roads area, and interested students should attend the Hampton Roads Sea Level Rise/Flooding Adaptation Forum at the Chrysler Museum on Feb. 18.

  • Norfolkbarry

    It appears that being an expert in oceanography does not mean you learn anything about geography. Norfolk’s problem with flooding is primarily related to subsidence, not sea level rise. In the first place, large parts of the city (including parts of ODU like Chandler Hall) are built on landfill, which merely covers the water that is under the soil. In the second place, the city resides over a fracture zone of the earth’s crust. which was caused by a large meteor impact millions of years ago. The area is sinking by a few millimeters a year: Norfolk and New Orleans are the two worst spots on the East Coast for land subsidence. Lastly, measuring sea level rise is not a trivial exercise, which should be obvious given only a moment’s thought: the earth’s tectonic plates that form the land and sea bottoms are not fixed in place but are constantly in motion and change. Exactly what relationship are we measuring? But don’t take my word for it, here is a link to a VIMS report on the subject of land subsidence in the Chesapeake bay area: http://www.vims.edu/GreyLit/VIMS/sramsoe425.pdf