Ocean load is pushing the seabed downwards

Scuba divers swim above a bed of corals off Malaysia's Tioman island in the South China Sea in May 4, 2008. Ocean load is pushing the seabed downwards. PHOTO | FILE | REUTERS

What you need to know:

  • A new study by a Delft University of Technology in the Netherlands indicates the sea bottom is hurting.
  • Among the components of the rise causes, at the top was the melting of the Greenland ice sheet.

  • This whole seabed warping though isn’t globally uniform.

One subject that features prominently because of global warming is sea-level rise.

A new study by a Delft University of Technology in the Netherlands indicates the sea bottom is hurting.

But first, how bad is the sea level rise? Six months ago, The Washington Post carried a story citing a Nature Climate Change report. It was headlined “Sea level Rise Isn’t Just Happening, It’s Getting Faster.”

What was 2.2. millimetres per year rise in 1993, the story said, became 3.3 millimetres in 2014. For those stuck in imperial measurements mindset, that’s a rise of 0.86 and 1.29 inches every ten years; not much on a tiled kitchen floor. A look at the globe indicates lots of water.

Among the components of the rise causes, at the top was the melting of the Greenland ice sheet. The same in smaller glaciers contributed.

Also in the neighbourhood was melting of inland ice caps, most of whose waters remained in inland seas, reservoirs, the Earth’s fauna and flora o flowed into oceans.

But what does the weight of that water do to Earth?  The Delft study, the latest of three on the subject published last year, didn’t go that far. It just looked at the ocean’s bottoms.

SINKING OCEAN

Calculation methods of the Delft study, published in the Science Alert, are beyond the scope of the discussion here.

However, essentially, the study indicates “the weight of all that extra water pushes down on the sinking ocean floor, deforming the seabed—and disguising just how much oceans are truly swelling.” Reason: existing measuring methods, including satellite, only indicate the surface goings-on.

‘’For roughly the last two decade (the period 1993-20140) the team calculates the increase in total ocean load has pushed the seabed by about 0.13mm  per year, or around 2.5mm (almost 1/10 of an inch) in total for the period,” the study shows.

This whole seabed warping though isn’t globally uniform. It indicates, though, scientists have been underestimating the sea-level rise.

DEFORMATION

As for the potential of the rise and the deformation of the seabed, for now, that’s for human beings’ imaginations gone wild.

These might be along the line of do the rising temperate, the melting ice and the warping seabed mean coastal lands and island nations will go up or under, ad infinitum.

Well, as of now only the Biblical Methuselah can tell. But whatever it is, it’s happening, albeit slowly.

Anyway, “The Earth itself is not a rigid sphere, it’s a deforming ball,” geoscientist Thomas Frederikse of Delft, the Earther quotes him.

“With climate change, we do not only change temperature.”