Was the MH370 floating debris field detected from orbit?

Was the MH370 floating debris field
detected from orbit?

Duncan Steel
2016 March 23rd

With the discovery of yet another apparent fragment of MH370 (this one at Mossel Bay, South Africa), it seems to be becoming clear that there was a large number (thousands) of objects in a floating debris field that escaped detection in the weeks after the crash. In my previous post I discussed how and why the airborne search may have missed the debris field. In the current post I will present some tentative evidence that the debris might have been detected from orbit using French satellites in a location consistent with a crash close to the 7th arc and between latitudes of about 34.5S and 38S, in a ‘gap’ in the airborne search areas. First, though, I will make some comments about the locations that are within the priority underwater search area, but (a) Have yet to be covered in that sea bottom search; and also (b) Were not covered in the airborne search.

Airborne and underwater search areas
In my preceding post I presented a map showing the 7th ping arc and the areas that had been subject to airborne search (through to 2014 April 25th). Various people have asked whether I could show also the area that has so far been covered by the sea bottom search. In the map below I do so:

Searched_areas

Map of areas searched from the air (through to 2014 April 25; grey background areas), overlaid with the areas of the sea bottom searched through to 2016 March 3rd (pink-hatched areas; thanks to Richard Cole).

The 7th arc shown above (in a Google Earth screen grab) is that pertaining to an assumed altitude of 35,000 feet. The KMZ file for that arc is available here.

Maps showing the areas covered day-by-day in the airborne search of the ocean surface are available from various websites, such as here. The KMZ file showing all areas south of 20S that were searched from the air was put together by Don Thompson, and is available here.

The lighter rectangle and grid with peripheral latitude and longitude markers I derived from Richard Cole’s latest underwater search status report, entitled MH370 Southern Indian Ocean Search Status 3rd March 2016. From that report I took a JPG screen grab of Map 4 (‘Full Search Area’) and stretched its colours somewhat so as to enhance the red component brightness. I then georeferenced the JPG image using GlobalMapper so as to produce a GeoTIFF version, and converted that GeoTIFF into a KMZ file using MyGeoData. The resultant KMZ overlay is available here.

In the map above I have made that overlay partially transparent in Google Earth so as to enable the airborne ocean surface search areas to be seen; this is also why I found it desirable to enhance the red colouration in Cole’s map. Those interested will likely find it useful to load the three KMZ files mentioned above into Google Earth or some other virtual globe application, because that will make matters clearer as one switches between the different overlays.

As Cole noted in an annotation to his Map 4, as as seen above, the pink areas are those that have so far (through to March 3rd) been subject to the sea bottom search.

I now draw attention to the areas indicated in the following map, where I have used bright green and turquoise lines to highlight these locations. The two areas delineated with bright green lines are within 40 nautical miles of the 7th arc (i.e. the laterally-extended ATSB ‘priority search region’) but have not yet been subject to an underwater search (i.e. they are not hatched in pink in Cole’s map), except for a few passes by the underwater search ship Discovery. The significant point here is that these areas were not subject to an airborne search either, in the six/seven weeks following the loss of MH370.

A similar statement applies to the two areas indicated using turquoise lines. The priority search zone is limited to that area within 40 NM of the 7th arc drawn as far north as 35.5S. Thus those two areas are outside of the present priority search zone, and have (mostly) not been subjected to either airborne or sea bottom searches.

Search_areas_missing

Map highlighting four areas (or just two, if you join the adjacent green and turquoise boxes together) that were not subject to airborne ocean surface search following the loss of MH370, and as of yet have not been subject to an underwater search. Thanks to Greg Hind for suggesting this comparison. 

The vital points here are:  (i) The area within the green and turquoise boxes represents a substantial fraction of the priority search zone, and so it would be incorrect to imagine that the underwater search is nearing completion; and (ii) The area within those boxes were not searched from the air either, and so the non-detection of a floating debris field by the airborne search crews is eminently feasible, if the aircraft did indeed crash in or near the priority search zone.

Note that in the above I have been considering only the airborne search of the ocean surface. I now turn to another type of search for floating debris: satellite imagery.

Satellite detection of floating material north of the 7th arc
Consider the screen grab shown below:

Southern_search_areas_updated


Note added 2016 March 24th: I have added a purple box to the map above. This indicates the areas searched on (2014) March 18 and 19 (see the next map below). Don Thompson points out that this vast area was quickly covered by only two aircraft, and it may be feasible that floating debris in that region was missed before the shift of focus to the region towards the southeast, in response to reported satellite imagery detections of debris, as discussed below. 


The aircraft swathes indicated within the area far south and encompassed by the yellow lines that I have drawn were flown as a result of apparent detections of floating material by Australian, Chinese, Thai and other satellites, and these were subject to many media reports and the publication of substantial numbers of satellite images. (Example reports and images: here, and here.)

All areas south of a latitude near 36S were searched from March 18 to March 27, as shown here:

Airborne_search_to_March_27

Subsequently (i.e. from March 28) the airborne search was switched to the larger areas shown in grey in the preceding Google Earth graphic, lying north of 36S.

It may well be that the lack of identification of any debris that might be linked to MH370 in the southernmost region through the aircraft inspections of targets found in satellite imagery prompted the investigators to abandon satellite imagery as a viable source of information, but when the switch was made from the southern search region to the region north of 36S it appears that certain floating items in a different location were not followed up either by aircraft or surface ships aiding the search.

On that point I stand to be corrected – perhaps the items that I describe below were indeed followed up but I have missed reports indicating that they were perused and concluded not to be associated with MH370 – but readers will find the location of these floating items to be pertinent, in the light of what I wrote above about the areas within the priority search zone that were not covered in the airborne search, nor have yet been covered in the underwater search.

I am indebted to Joseph Coleman for pointing out the satellite detections in question. Joseph sent me a small section of a photograph showing this:

French_Satellite_Images_locations

Eventually I was able to track down the full photograph; it can be seen here, and here, and here, and here. It is part of a slide shown in a next-of-kin briefing held on 2014 March 28 at the Metro Park Lido Hotel in Beijing, the rest of the slide indicating other areas where satellite detections of floating objects had been made.

Whilst the above positions were apparently obtained on 2014 March 23rd, the first detection of debris in that general location was made on March 21st; the following map was published by the BBC on March 23rd (i.e. before any further detections on that date might have been made public):

BBC_MH370_23_March_2014

The above detection – that of March 21st – was apparently made using a French radar satellite, according to media reports (see here, and here, and here); see also this Malaysian Government announcement. The satellite may well have been TerraSAR-X, a joint French-German project.

Although the situation gauged from media coverage is confused, various reports indicate that the radar detection was followed up by French imaging satellites (presumably Pléiades A and Pléiades B) on March 23rd, with “122 objects” being seen. This panoply of items was presumably detected in the main around the locations of the red dots in the map below, which appeared on BBC webpages on 26, 27 and 28 March (such as here, and here, and here, and here), and perhaps others. How the four or more objects located at or around the northernmost black dot in this map relate to the other 122 is not clear.

BBC_MH370_28_March_2014

Based on the discussion above on unsearched regions (from the air, or underwater), readers will recognise that the northernmost black dot in the above map from the BBC is in an area of some interest; and yet that is a location where there was information on floating objects detected on March 21st and the 23rd also (the slide presented at the next-of-kin briefing on March 28th gives four rather-precise geographical locations and states that the items were sighted on March 23rd). The locations given can of course be plotted in Google Earth  for comparison with the underwater priority search region, and the areas searched (or, not searched) from aircraft. Here is the region of interest:

French_satellite_debris_locations

The pins labelled F1, F2, F3 and F4 above indicate the locations of four floating items detected by means of French satellite[s] (whether radar or optical imaging is not clear to me, yet!) on 2014 March 23rd; and presumably nearby on March 21st also. A KML file containing those locations is available here.  

Whilst there are many satellite images of floating debris in the southernmost areas that are available on the internet (for example, here), as of yet I have been unable to find any of the reported ‘French’ images pertaining to the above four items (nor indeed the larger set of 122).

For the present I will say little more, except to note that the locations of these floating items – perhaps debris from MH370 – is consistent with the order-of-magnitude speed and direction (between north and northeast) of oceanic drift through to March 21/23 from a crash on March 8 somewhere within the north-of-the-7th-arc green and turquoise zones identified earlier in this post (which were not surface-searched by aircraft soon after the crash, and are yet to be sea-bottom searched).

A subsequent post will deal with drift modelling in this region by other Independent Group members.

The reader can draw his/her own conclusions as to what the above might indicate. It would be useful and helpful if the official investigators could indicate whether the locations of the four (or more?) reported floating items near 35S, 091E were searched either from the air or by a surface ship in a timely manner (i.e. before the airborne search was shifted northeastwards from March 28th, and before any floating debris field might disperse). Were the four items spotted thereabouts by the French examined, and discounted as being parts from MH370?

Even at this stage it might also be helpful if those with access to satellite imagery for the location and time in question were to re-examine their pictures. (Thanks to Annette in Australia for this suggestion.) If the four French-found objects were not followed up at the time, then a vital indicator of where MH370 went down may have been missed. However, the situation might not be irredeemable: if a plausible floating debris field were identified in such imagery obtained two years ago, then it would be close to where MH370 crashed, and to the north or northeast of the crash site by a distance which can be estimated on the basis of typical drift speeds.