Wednesday, September 23, 2015

Proof of Concept - 2

Fig. 1 SQL query on PSMSL data
I. Background

The high energy readers of this blog, every once in a while, need to see a strong revelation into the type and standard of evidence Dredd Blog uses.

I tend to think that I use reliable evidence, however, in order that readers get what they expect and deserve, today's post is a display of why I think the information I tend to use reliable.

This is an obligation that all bloggers have to readers, so the readers know where bloggers are coming from, and so readers do not waste their time.
Fig. 2 Ready for graphing

So, today I will deal with one of those things Professor Mitrovica of Harvard described as "the most counter-intuitive" research results in his career.

The basic issue is sea level fall (SLF) when everyone is talking about sea level rise (SLR), especially in the area of today's discussion, a place where sea level is dropping, but more mysteriously, a place where they don't seem to know why (Southern Alaskan sea levels defy worldwide trends).

In other words, "the whole world is talking about sea level rise but we aren't getting any."

If they read this post, perhaps they will forego becoming deniers.

We can hope.
II. The Good Stuff

Let's begin at the beginning, an SQL query into tons of data I acquired from the wonderful tide gauge records source PSMSL, then placed into a mySQL database on one of my computers (Fig. 1 click on any graphic to enlarge).
Fig. 3  Are we done yet?

I then copied it from the terminal screen into a text editor and did some sneaky "find / replace" machinations to convert it into a .csv file (Fig. 2).

Which meant I could then import it into a graph program and generate so line graphs aplenty.

The raw display of fields or columns named "lat,highsl,lowsl" (latitude, high sea level, low sea level) was generated as shown in the graph at Fig. 3.

That graph tells us that at some of the latitudes in GeoZone "np" in Alaska, at some of the tide gauge station locations (notably near Lat. 58 W) the has been some serious SLF.

Which ones are they?
III. The Better Stuff

Fig. 4 Fingerprints of Glacier Bay
The readers of Dredd Blog do not have to figure that out using only the raw data discussed so far.

Since we are in a proof of concept mode, involving the ghost of sea level science (SLF), and since Dredd Blog readers are so demanding, I had to go the extra mile folks.

I just had to produce the details in a graph editor, so you did not have to, and then display the results at Fig. 4.

Fig. 5 Yep, definitely SLF
I labelled the strong SLF area  (Yakutat, Skagway, Juneau). and areas west and south of there, which are further away from the ice masses (Sitka, Ketchikan, Prince Rupert).

Fig. 6 Yep, definitely SLF
For the other stations returned in the SQL query, I placed their station number on the graph, which you can double check with a comparison to Fig. 1, which has their identity data displayed.

I also lined up the latitude numbers, located at the bottom of the graph, to the tide gauge station numbers for each of the latitudes shown.

The bottom line is that this data confirms the fingerprint hypothesis, confirms that fingerprint sea level change (SLC) science is for real, and the software and database are useful tools for future inquiries.

IV. Conclusion

In the previous post I included a graph of the years of records concerning the tide gauge station at Yakutat, so in Fig. 5 and Fig. 6, I did so for Skagway and Juneau as well.

There is no doubt about the evidence used on Dredd Blog for the benefit of all Dredd Blog readers.

At your service.

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

Dr. Jerry Mitrovica on the fingerprints of SLC:


  1. Fig. 3 and 4 are WHERE graphs.

    Fig. 5 and 6 are WHEN graphs.

  2. I updated Fig. 1 and Fig. 2 because the image was a bit blurry.

    They are easier to read now.

  3. Nice work Dredd!


  4. BTW, the difference in Skagway's high SL of years ago, and low SL now is about 4 ft. 3 inches.