|Fig. 1 Axis shift induced sea level rise|
Warming climate changes that cause polar ice sheets to melt, to weaken, and to shift gravity.
Today, I want to talk about an effect that will impact two areas of the globe with sea level rise (SLR), focusing on one such area called "the United States of America" or USeh?:
Polar ice sheets are not located symmetrically on Earth’s poles. Therefore, in light of their huge mass, Earth’s axis of rotation changes as they grow or shrink. Jerry Mitrovica has calculated that if the West Antarctic Ice Sheet [WAIS] melted in its entirety, the southern pole of Earth’s axis would move about half a mile toward the tip of South America. This change alone would raise sea level about 4 feet in two roughly circular regions, one in the Indian Ocean and the other centered on the US. This calculation demonstrates that movement, or wandering, of the poles is a substantial effect. It also demonstrates another way that changes in sea level are highly variable around the globe. Mitrovica takes polar wandering into account when inferring the relationship between changes in local sea level since the Pliocene observed at Pliomax sites and global average sea level change.(Axis Upheaval, emphasis added; cf. Fig. 1 & video below). As most people who concern themselves with SLR know, the WAIS is melting faster than East Antarctica is.
|Fig. 2 Potential SLR with source locations|
This 1.22 m / 4 ft SLR, which Dr. Mitrovica identifies (see Fig 1), would not be the result of the meltwater coming from the WAIS.
If you notice Fig. 2, SLR from WAIS meltwater would be 26.44 feet.
Thus, the extra 4 ft. from the axis shift is superfluous, because substantial catastrophe takes place at about 1m / 3ft of SLR (A Paper From Hansen et al. Is Now Open For Discussion).
But, what it does serve to illustrate is that there are more forces associated with melting ice sheets than meltwater and icebergs alone.
|Fig. 3 Who needs 4ft more of SLR?|
They are all linked together, acting as synchronized global phenomena, with a surprising percentage added onto meltwater and iceberg SLR impacts.
A previous post details what is shown in Fig. 3 in the Chesapeake Bay area, where "at least 13 islands" are already submerged (Will This Float Your Boat - 10).
The 4ft. axis shift (Fig. 1) is (4 ÷ 26.44 = 0.15128593) ~15% as much SLR as the entire melted ice sheet engenders ( 0.15128593 * 100 = 15.13%).
That 15% is not caused by additional meltwater entering the sea, rather, it is caused by a "bulge" (gravity, centripetal force, etc.) explained in the video below.
It would seem to me that this means there may be an additional up to ~15% SLR impact at any given time which we can add to meltwater or iceberg SLR calculations.
That is because this phenomenon is happening all the time, as the ice almost imperceptibly melts, the axis location almost imperceptibly moves causing the SLR bulge to move toward the U.S. too (e.g. Antarctic Gravity Data and Gravity Shift Reveals West Antarctic Ice Loss).
The location shown in Fig. 1 is its final quantity of SLR and final destination, after all the WAIS melts or calves into the sea.
But, as it melts from 25% to 50%, then on to 100%, the bulge effect is constantly moving in the ocean, from where it is now to where it will eventually end up.
There are additional forces associated with the ice sheet melt and disintegration, such as sub-glacial land mass uprising as the ice sheet, which now suppresses it downward, gets lighter and lighter (Is A New Age Of Pressure Upon Us?, 2, 3, 4, 5, 6).
We have even witnessed recently, with our own eyes, a volcanic eruption as a result of a glacier in Iceland melting to such a degree that it could no longer suppress the magma below the bedrock the sheet rested on, because it became too thin (e.g. Global Warming & Volcanic Eruptions).
The melting in Greenland, and other locations in Antarctica, will change, accelerate, or otherwise impact upon the bulge locations, depending on which melts first and/or melts most (The Gravity of Glacial Melt).
That we are consistently having "the warmest year" each year now, means that there will be ongoing increased impact year by year.
Increased fossil fuel use also increases the ice melt on the warming globe.
The next post in this series is here, the previous post in this series is here.
Professor Jerry X. Mitrovica on the gravity / axis bulge SLR issues we don't hear about often: