Thursday, January 4, 2018

Is A New Age Of Pressure Upon Us? - 14

"Fingerprints" of crustal stress
In the previous post of this series on the Dredd Blog System, I detailed the history of this question going back almost eight years.

In that post I pointed out the gist of this subject:
"The impacts I am now talking about are the changes in pressures upon the Earth's crust which take place in a very wide span of the ocean basins.

Those impacts concern both a decrease in pressure in some areas, as well as an increase of pressure in other areas."
(Is A New Age Of Pressure Upon Us? - 13). Like the ghost water discussions here on Dredd Blog were substantiated (NASA Busts The Ghost), a recent paper now upholds the pressure change hypothesis (Ocean Bottom Deformation Due To Present-Day Mass Redistribution and Its Impact on Sea Level Observations, PDF).

The basic idea in that cited paper is that there is more sea level rise taking place than our current measurement technology records show, because increased pressure even changes the depth of the ocean a tiny amount.

That is because the bottom of the ocean is sinking due to additional weight placed upon it by the mass increases due to ice sheet and glacial melt.

We can add to that the additional reality that as the ghost water leaves the area of an ice sheet because of loss of gravity, as the ice sheet melts, the ocean floor in that area will rise, causing even more water to relocate towards the equator (a feedback loop).

The paper cited above also agrees with that hypothesis:
"The rate of elastic subsidence shows distinct spatial features: an uplift signal is present close to the major melt sources around the Arctic Ocean, Alaska, and the West Antarctic ice sheet. A north-south gradient is visible in Figure 2a, with large parts of the Northern Hemisphere oceans showing uplift, while most of the Southern Hemisphere is affected by a subsidence rate above the global mean. This ocean bottom deformation signal determines a large part of the regional variability of the resulting relative sea level changes depicted in Figure 2b, especially close to the major ice melt sources, while the variations in geocentric sea level changes, for which the regional variability is only determined by geoid changes, show smaller spatial gradients (Figure 2c). Therefore, the largest differences between relative and geocentric sea level can be found in high-latitude areas close to the major ice melt sources."
(ibid, p. 4, PDF). But, all that being said, the amounts are small.

My guestimation being 0.01 mm year additional global mean average sea level rise (GMSL) since circa 1880 (about 1.37 mm).

But, GMSL aside, the increase will be much more at the maximum sea level rise areas far from coastlines.

After further study I will try to establish a more concrete calculation, but in the mean time I will stick with actual tide gauge records.

The big impact, which is the subject of this series, is the stress on the Earth's elastic crust which can and does cause both earthquakes and volcanic eruptions in the most sensitive crustal areas (Is A New Age Of Pressure Upon Us?, 2, 3, 4, 5, 6, 7, 8, 9, 10,11, 12, 13).

It's Humble Oil-Qaeda at work softly killing civilization.

The previous post in this series is here.

9 comments:

  1. "Tsunami warning in effect after 8.2-magnitude earthquake off Alaska coast" (link)

    ReplyDelete
  2. http://www.sandiegouniontribune.com/opinion/the-conversation/sd-california-tsunami-history-20180123-htmlstory.html

    This Alaska earthquake ...

    ReplyDelete
  3. "Powerful volcanic eruptions will likely get more frequent in the future scientists say"

    http://www.businessinsider.com/volcano-eruptions-increase-japan-philippines-warming-climate-glacial-retreat-2018-1

    ReplyDelete
  4. "Hawaii volcano raises concerns of eruptions along West Coast" - ABC News

    ReplyDelete