NOAA Agrees: Axes 7th Arc

NOAA has just single-handedly NUKED the Seventh Arc that underpinned Australia’s search for nearly three years. But NOAA didn’t come out and actually say it abandoned the 7th Arc. Instead, the agency put an “X-marks-the-spot” on the second of two rather ambiguous charts in a way that makes it harder to figure out what they did. The first of those charts was published here on December 14, 2016:

Following in ATSB’s footsteps, the “keep it a secret” theory apparently is, “don’t say it and they won’t realize you didn’t get the transparency memo”.

Here is the latest chart NOAA is pushing:

NOAA drift chart for MH370 debris analysis published in revised form under original date.

Anyone can take a stab at trying to figure out where the fat red squiggle intersects the “final Arc” west of Exmouth. But I’ll use a firing-range tool in the hope of being a bit more precise: crosshairs. Doing it that way, we will ALSO see NOAA is no longer on the 7th Arc.

NOAA drift chart for MH370 debris analysis published in revised form under original date. Crosshairs added to identify GPS estimate.

From the above, we know NOAA is now on the 6th Arc, not the 7th. Sorry, can’t overlay the 6th Arc on it; please take my word for it for now.

Why the Green-Frame Selection Box?

While I personally have many reasons for hoping NOAA’s latest “crash location” is close to the mark, it is nevertheless important to consider a few of the reasons it is likely to change, at least a little.

Researchers design studies in all kinds of ways. Some are constructive and lead to useful information. Some are not well considered and need to be refined. Some are designed so poorly there is no hope of “fixing” them. This NOAA study needs to be refined, and it can be refined. It wouldn’t hurt to also eliminate a lot of faux intellectual / academic gobbledygook at the same time.

  1. NOAA likes “selection boxes” like those shown above in green and magenta; but when overlaid on active substrates like ocean surfaces, selection boxes can be misleading at best because they attempt to still-frame what is in reality a moving / changing sub-population of NOAA drifters. (I have no problem with the magenta selection box. It marks the end-point and needs to be static.)
  2. There was a good reason for using selection boxes when NOAA first began using them in the 1900s: USDA did it first and arguably best. USDA is where Fisher Statistics were developed (normal distributions). But NOAA tried to implement the concept without adapting it to a fluid environment. So selection boxes, known as “plots” in USDA parlance, became common US inter-agency government tools for decades. But the plot concept doesn’t always translate well from a static environment like a garden or field, to a fluid environment like an ocean surface. NOAA appears to have failed to take that into consideration when designing many of its studies right up to the present time. 
  3. The result is a longstanding practice that is less than robust.
  4. For example, a NOAA drifter buoy that bobs into the green box on the east side, does not have the same probability of doing anything the same way a NOAA drifter buoy will if it enters from the southwest corner or the west side of the selection box. What is the research goal? Is it to be able to comment on buoys that crossed the final arc AND ended up near Reunion Island? If it is, select only drifter buoys that actually cross the final arc, anywhere along that 4,000 km arc (or explain why you are taking a different approach).
  5. Perhaps the biggest problem with NOAA’s construct is that the green selection box does NOT encompass all “at risk” Final Arc buoys. To do that, it has to begin at Java and extend all the way down to -40°S. Looking at the large group not currently selected (southwest of Java), it is certain that those drifters will move NOAA’s endpoint northeast if they are ever included in central tendency metrics.
  6. No drift study of MH370 debris can be thorough / robust if it ignores the impact Cyclone Gillian had on that debris field in late March 2014. Other Indian Ocean storms appear to have had a negligible impact. Gillian’s impact was profound.

What Is The Point?

Exactly. What is the point of selecting only a partial sample of drifters crossing the final arc? It needs to be explained. Otherwise, it appears to be a poorly considered model no one in the peer review chain caught. Or was it even peer reviewed?

Important to remember how CSIRO’s David Griffin used a selection box in his initial drifter study. He put a much smaller selection box way down at the southern tip of what was then the Seventh Arc search area. Doing it that way biased his whole study by ensuring that his findings would point to the now fully discredited original search area. (I have argued that Griffin intended to bias the study. I still believe that is what he intended to do. Alternatively, Griffin has no idea how to design a useful empirical inquiry.) 

This latest NOAA study is a little better; but still doesn’t include the entire final arc sub-population of drifters. In essence, this study is suggesting there is no chance the plane crashed north of about -15°S. That is patently false. While my own work suggests the Batavia to Zenith area is generally correct, it is not helpful to try to support my own work with findings based on questionable methodologies. That is precisely what kept us south of Broken Ridge for three years, and it is precisely why we have nothing to show for all of that time and effort.

In summary, NOAA needs to refine its methodology, give equal weight to all drifters that cross the final arc (the 6th Arc is right but it has to be a calibrated 6th Arc). The raw 6th Arc published by Inmarsat in 2014 is NOT correct. Does not matter that it is a relatively minor error. It will greatly influence the seafloor that is or is not scanned.

Comments are closed.