Build Your Own Sea Level Change Fingerprinting System

Fig. 1

My previous post was placed into an ongoing series here at Dredd Blog which concerns "fingerprints" of sea level change (SLC Fingerprints R Us - 3).

This new series, which today's post begins, is going to be about the analysis of the data presented in that post à la another Dredd Blog series (Build Your Own Thermosteric Computational System, 2).

As I begin this series and this post, I have not come to any conclusions as to whether or not "fingerprints" of ice sheet melt can be detected from the analysis of all PSMSL station data within a collection of WOD Zones.

Fig. 2

The main reason I have no conclusion is that I have not analyzed the data yet, nor have I developed a process with which to analyze the zone data.

The analysis is going to be done post by post, as I write down the process I am going through in order to develop a reasonable conclusion.

It will hopefully become a process that can be used on other WOD Zone collections and by bloggers other than myself.

So, let's get started.

First, notice the graphic at Fig. 1 which is derived from a published paper (Tamisiea, M.E., and J.X. Mitrovica. 2011, Oceanography PDF).

That paper, presented in the peer reviewed Oceanography Magazine,  gives a comprehensive background as to why sea level does not change the same amount everywhere, contrary to the outdated "bathtub model" (The Bathtub Model Doesn't Hold Water, 2, 3, 4, 5).

Fig. 3a Zone 1314 up to yr 2010

Fig. 3b Zone 1314 after Fukushima quake

It also discusses sea level change "fingerprints."

Anyway, I enhanced that graphic, which depicts probable sea level change fingerprints, so that we could see what might be expected at each zone, in terms of types and amounts of sea level change (i.e. rise or fall).

I did the enhancements by adding some latitude and longitude lines, and by adding some arrows that point to the locations of the collection of WOD Zones shown on Fig. 2 (the WOD Zone map with the zones outlined by red rectangles).

The left side of the graphic @ Fig. 1 is Greenland impact, and the right side is West Antarctica impact.

By comparing Fig. 1 and Fig. 2 with the graphs of the maximum and minimum sea level change in those zones, perhaps we can detect some "fingerprints."

The colors represent the impact that Greenland and Antarctica ice sheet melt water has at various places around the globe, after being relocated there by gravity and the force of the Earth's rotation.

Moving along, note that the first thing to do in the analysis process is to check for "radical departures" in the station data (compare Fig. 3a with Fig. 3b).

That we do by noticing any anomalies in the graphs.

One of the graphs (Fig. 3b, corrected version @ Fig. 3a) had anomalous data for the years following 2010 (March 2011 Tohoku (Fukushima) Earthquake related?).

The tide gauge stations may have been moved up and/or down during the subduction event that caused the quake at 38.3 degrees North latitude and 142.4 degrees East longitude (Is A New Age Of Pressure Upon Us?, 2, 3, 4, 5, 6, 7, 8, 9, 10,11, 12, 13, 14, 15).

The PSMSL says this about it:

"A massive earthquake magnitude 9.0 occurred at 14.46 JST (05.46 UTC) on Friday 11th March 2011 with the epicentre situated approx. 70km east of the Oshika Peninsula of Tohoku. It was the largest earthquake ever to strike Japan and triggered a tsunami with waves of up to 40.5m travelling inland up to 10km. From the data plot it can be seen that obviously the tide gauge was badly damaged. Data following the earthquake flagged."

(RE: Station #1346, emphasis added). Other tide gauge stations in WOD Zone 1314 were also flagged (see Zone 1314 data here).

Anyway, with as level a playing field as we can determine at this point, we can move on to compare Fig. 1 and Fig. 2 locations with the graphs in the post that contains the WOD and PSMSL data (SLC Fingerprints R Us - 3).

Before closing for today, let's analyze WOD Zone 1313 and WOD Zone 1314 (off the coast of Japan).

The high value for WOD Zone 1313 is 652.29 mm and the low value is -535.5 mm (652.29 - 535.5 = 116.79).

The high value for WOD Zone 1314 is 1090.95 mm and the low value is 181.71 mm (1090.95 − 181.71 = 909.24).

Notice that Zone 1314 is in the red spot in the graphic on the left side of Fig. 1 (indicating maximum impact from Greenland), while Zone 1313 is only in the orange color.

This fingerprint tells us that more Greenland melt water has relocated to Zone 1314 than Antarctica melt water has.

See if you can follow this analytical technique in the other graphs (I haven't done that yet).

The next post in this series is here.