Is A New Age Of Pressure Upon Us? - 13

Fig. 1 A seismograph becomes a trend-o-graph

I. Background

About 7.5 years ago I penned Global Warming & Volcanic Eruptions.

Shortly following that (about a month later), I began a series on the issue.

This series has covered the subject over the several years since its inception (Is A New Age Of Pressure Upon Us?, 2, 3, 4, 5, 6, 7, 8, 9, 10,11, 12); however the last post in this series (#12) took place almost a year ago.

So, today we continue the discussion of this important, overlooked, but strongly ongoing issue (Fig. 1).

II. Not Much Mediocrity Mediacrity Has Changed

As the USGS reports, not much has changed, except perhaps that in the last few days

Fig. 2 More graphs here

earthquake coverage has inhabited the mass mediasphere.

As has been said, "All I know is just what I read in the papers, and that's an alibi for my ignorance." Will Rogers

Which in whole or in part can lead to a particular world view as to what is important and what is not  ("The old newspaper adage, 'If it bleeds, it leads,' is as true today as it was a century ago." Peter Diamandis); thus, foreseeing an oncoming reality becomes less important than reacting to it once it has arrived, because the media disdains foresight as it clings to bleeding breaking news.

III. Some New Insights On Old Insights

This series has focused on the reality that there is more than meets the eye concerning the actual nature of the impacts of sea level change.

For example, there is more than merely impacts to coast lines and coast line maps, more than refugees having to move further inland, and more than the ongoing and upcoming retreat of world seaports (The Extinction of Robust Sea Ports, 2, 3, 4, 5, 6, 7, 8, 9).

Fig. 3 Humble Oil-Qaeda

The impacts I am now talking about are the changes in pressures upon the Earth's crust.

Those impacts concern both a decrease in pressure in some areas, as well as an increase of pressure in other areas.

One reason for that type of change is that the great weight of ice sheets releases pressure from the land beneath them as they melt and flow into the ocean.

Their watery residue then creates pressure in various far away places where their melt water has relocated to.

Not only that, the loss of their gravity, which was once pulling water toward and upon them, frees that large quantity of water from being bound up against them (The Gravity of Sea Level Change, 2, 3, 4).

This phenomenon is not limited to the waters around Greenland and Antarctica (Proof of Concept - 3).

That once-gravity-trapped water will then flow away from its place to decrease pressure there, but to increase pressure elsewhere (The Ghost-Water Constant, 2, 3, 4, 5, 6, 7, 8, 9).

"So what?" you may wonder.

IV. The Answer

The previous question is answered by "glacial isostatic adjustment (GIA)" as discussed in Mitrovica, et al., (2015), a PDF file.

The bidirectional up and down GIA causes torque, stress, and tension between crustal movement upwards and crustal movement downward.

Likewise, the speed-up and slow-down of the Earth's rotation, as a result of those changes in the Earth's shape, also cause additional torque, stress, and tension on the crust (ibid).

Those rotational speed changes cause changes in shape that engender a shape that is closer to a perfect globe, for awhile, then other speed changes make further changes to a shape that is closer to an imperfect globe shape.

Those contortions and changes force, in various degrees, a release of impediments to earthquakes and volcanism in some places, while impeding, in various degrees, earthquakes and volcanism in other areas.

V. Conclusion 

Remember that the 1750 Industrial Revolution began to inject greenhouse gases into the atmosphere long ago, which has increased climate and sea level change since then.

As the graphs in earlier posts of this series show, seismic and volcanic activity have also increased during this, the Anthropocene (Fig. 2).

The next post in this series is here, the previous post in this series is here.

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Who knew (Fig. 3)?

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On The More Robust Sea Level Computation Techniques - 2

Fig. 1a

I. Background

I have been surprised by the outcome of using the TEOS-10 thermodynamics toolkit.

Fig. 1b

As regular readers know, for the longest time I calculated thermal expansion caused volume change as a percentage of sea level change.

Fig. 1c

That percentage was 5.1% calculated from actual sea level change minus the ghost water percentage.

Even that 5.1% was lower than current establishment science calculates, which was said to be more than sea level change caused by the melting of the Cryosphere.

II. Along Comes TEOS-10

Looking for possibly a more accurate way to calculate the percentages that thermal expansion and contraction (thermosteric) contribute to sea level change, I ran across the TEOS-10 Toolkit (TEOS-10 Website).

I made various experimental attempts to calculate thermal expansion values with the TEOS-10 toolkit, partnering it up with the traditional formula for such calculations and WOD, PSMSL, and GISS data.

Fig. 2a

Then I came across a bombshell paper which narrowed down the remaining techniques to two.

Fig. 2b

That bombshell paper pointed out the following:

Fig. 2c

"A common practice in sea level research is to analyze separately the variability of the steric and mass components of sea level. However, there are conceptual and practical issues that have sometimes been misinterpreted, leading to erroneous and contradictory conclusions on regional sea level variability. The crucial point to be noted is that the steric component does not account for volume changes but does for volume changes per mass unit (i.e., density changes). This indicates that the steric component only represents actual volume changes when the mass of the considered water body remains constant."

(On The More Robust Sea Level Computation Techniques, quoting from JOURNAL OF GEOPHYSICAL RESEARCH: OCEANS, VOL. 118, 953–963, doi:10.1002/jgrc.20060, by Gabriel Jordà and Damià Gomis, 2013; @p. 953, 954, emphasis added). That certainly can change things.

III. Along Comes New Graphs

And so, today's graphs are presented to show the stark difference between the results of those two techniques mentioned in the paper.

Fig. 3a

The graphs are numbered in Fig. 1, Fig. 2, and Fig. 3 groups, each group having an 'a', a 'b', and a 'c' member graph.

Fig. 3b

The 'a' member of each graph group is in compliance with the paper quoted above, which sternly points out:
"The crucial point to be noted is that the steric component [thermosteric] does not account for volume changes but does for volume changes per mass unit (i.e., density changes). This indicates that the steric component only represents actual volume changes when the mass of the considered water body remains constant." (ibid, emphasis added).

Fig. 3c

In other words, one must calculate the ocean volume from the 1st year a calculation of sea level change commences.

Then one must use that same quantity throughout all the other years of that span of time being calculated and graphed.

That is, the increasing and decreasing sea levels (ocean mass and volume changes) over a span of time are not to be used if one seeks to present an accurate estimation / calculation of thermosteric volume change over that span of time.

IV. The Tide Gauge Station Selections

In these graphs I present the two techniques using three lists of tide gauge stations: Fig. 1 group) 491 stations used by Church & White (2011), Fig. 2 group) all stations (1,484), and Fig. 3 group) "the Golden 23".

The 'a' member in each of those three groups shows the calculation mandated by the paper quoted in Section II.

As you can see, the thermal expansion calculations show significantly less sea level change caused by thermosteric dynamics than the old Dredd Blog 5.1% method shows.

Yikes !

Can "thermal expansion as the main cause of sea level rise in the 19th and 20th centuries" be that much of a myth?

V. How I Process The Data

I won't go through the arduous task of building a billion rows of SQL based data after downloading that data from PSMSL, WOD, and GISSTEMP.

I won't go through the software architectural work of designing software modules to analyze that data.

Today, let's just look at how the completed modules handle that data, beginning with TEOS-10 functions.

First we acquire in situ (at a specific latitude, longitude location) temperature along with in situ salinity ("practical salinity") readings from a specific ocean depth at that location.

Let's call them 'T' (temperature) 'SP' (practical salinity) and 'Z' (a depth or 'height' in TEOS parlance).

First we convert those in situ values into TEOS values:

1) Z into P (pressure) using the TEOS function P = "gsw_p_from_z(double z, double lat)";

2) S_A using  S_A = "gsw_sa_from_sp(double sp, double p, double lon, double lat)";

3) T into "conservative temperature" CT = "gsw_ct_from_t(double sa, double t, double p)";

Now, we can calculate the all important "thermal expansion coefficient"
(symbol 'β') β = "gsw_alpha(double sa, double ct, double p)".

Last but not least, we use a traditional formula for calculating thermal expansion / contraction volume change: V₁ = V₀(1 + β ΔT) as I noted early on in the struggle:

The one I settled on is: V₁ = V₀(1 + β ΔT), where: V₁ means new volume, V₀ means original volume, β means temperature coefficient, and ΔT means change in temperature (T₁ - T₀), which is another way of "saying" dV = V₀ β (t₁ - t₀), a formula in widespread use (Engineering Toolbox, cf here).

(On Thermal Expansion & Thermal Contraction - 18). When calculating a long span of years, the "ΔT" becomes the previous years temperature minus the current year's temperature (change in temperature), or vice versa depending on the direction (backwards in time, or forward in time) in which you are calculating.

VI. Discussion Of The Graphs

The 'a' member of each graph group features what happens when the mass-volume (V₀) remains constant as conservative temperature (CT), absolute salinity (SA), and pressure change over time.

The 'b' member graphs the temperature and salinity changes.

The 'c' member shows what happens when the volume (V₀) changes along with the temperature and salinity.

The difference in the thermal expansion / contraction is dramatic between the two usages (constant volume, variable volume).

VII. Conclusion

There is more work to do to figure out just how the oceanographers calculate thermosteric volume.

Any suggestions?

The next post in this series is here, the previous post in this series is here.