So much of Earth is covered by sea, great blue expanses dotted here and there by land. Their depths are the most mysterious and unexplored places left on the Planet, and they are filled with life.
The sea bed is not a rigid, impenetrable plate separating the waters from a solid inner core, but is a moving, changing skin that expands and contracts in accordance with the needs of the living globe it protects; sometimes, indeed, the sea bed breaks open, just as the skin on our bodies reacts and changes and is wounded according to the pressures put upon it. We tend to take the sea bed for granted, just as sometimes we dishonour our own physicality: overlooking it could be a costly mistake.
A new report in “Geophysical Research Letters” confirms that the ocean bottom is elastic and changing, and that the trend for “deformation” of the sea bed will grow with climate change. As glaciers and ice sheets melt increasingly rapidly, so the mass of ocean water increases and the extra weight presses down on the floor of the ocean, causing it to sink more and more over time. Until now, rising sea levels have been calculated from measuring the surface, not taking into account erosion in the depths. The overall rise in sea levels and quantity is likely, therefore, to be far greater than realised until now, and scientists are worried.
The implications are significant. The undermining of the sea bed could lead to fissures that release the waters held in underground seas and lakes; movement of tectonic plates could be amplified; earthquakes and volcanic eruptions could be triggered; and land could be forced to rise in the same way that mountains were formed and islands created. If, too, the sea bed reaches its limit of elasticity, sea levels would be affected dramatically.
Some of these scenarios could occur soon, others would take a lot longer, and they depend on the premise that glaciers and ice sheets will continue to melt. I am in a minority, I know, when I say that I do not believe global warming will continue as predicted, but that we are entering a mini ice-age instead – climate change of a very different nature that is partially caused by man, and partially as a result of the natural cycles of nature Earth has experienced since her birth.
For now, sea levels will continue to rise and the sea bed will be under pressure, with potentially serious repercussions. The new awareness of the sensitivity of the ocean floor and its importance may encourage greater care in how we use and treat these precious depths. They hold many secrets, and have guarded us well. They deserve our care, and our respect.