The search for MH370 and ocean surface drift
Executive summary - Report 1
This report details the results of a comprehensive attempt to use drift modelling to inform efforts to locate the missing Malaysia Airlines flight MH370 (registered 9M-MRO). It differs from earlier attempts to do this in several important ways, which, along with other developments, have enabled it to come up with a location of the aircraft that is much more precise than we thought was possible.
We have concluded that the northern third (from 36°S to 33°S or perhaps 32°S) of the initial search area uniquely remains prospective. This northern area was partially searched (close to the 7th arc) in the latter half of 2014 and early 2015. Locations outside the searched area, but still within a likely distance from the arc, remain unsearched. The region near 35°S is particularly prospective because there is strong evidence (from Earth-observation satellite data) that this is where, at the time of the accident and for weeks after, the debris field would have been carried north-west for about 500km, away from where the March-April 2014 surface search was conducted and away from the shores of Western Australia (WA). The scenario of a final location near 35°S is the one that is most consistent with:
- the absence of debris findings on the WA coastline
- the absence of debris findings during the aerial and surface search
- the July 2015 arrival time of the flaperon at La Reunion
- the December 2015 and onwards (only) arrival times of debris in the western Indian Ocean.
The uncertainty of this finding has been greatly reduced from what was possible earlier by:
- measuring the wind-driven drift rate of replica aircraft parts alongside oceanographic drifters (whose travel times across the Indian Ocean are well known), and
- using a new ocean model that is informed by very accurate satellite measurements of small perturbations of sea level, yielding estimates of surface currents that have been validated using the global archive of oceanographic drifters.
Are other regions also prospective?
If the flaperon had remained the only piece of debris found we would have to say ‘perhaps’, but now many debris items have been found, we can conclude that regions north of 32°S and south of 39°S are both less likely. Drift modelling suggests that debris items originating north of 32°S would probably have been detected by the surface search, and that items would have probably arrived in Africa before December 2015. Regions south of 39°S are not prospective either, because debris from those regions would more likely have turned up on Australian coastlines than west Indian Ocean ones.