A Stable Isotope Sclerochronology‐Based Forensic Method for Reconstructing Debris Drift Paths With Application to the MH370 Crash

Abstract

A flaperon belonging to Malaysian Airlines flight MH370 washed ashore on Réunion Island covered with the barnacle Lepas anatifera in July 2015, more than a year after the plane's disappearance. Here, we report the first high‐precision δ ¹⁸O _calcite versus temperature relationship for L. anatifera reared under laboratory conditions to unlock clues to the flaperon's drift path and origin. Using this experimental relationship and known growth rates for L. anatifera, we also demonstrate a new method for (a) converting δ ¹⁸O data for one of the MH370 barnacles into a dated time series of sea surface temperatures (SSTs) experienced during the last part of the flaperon's drift and (b) identifying best fits between the observed flaperon SST time series and 50,000 SST histories generated from a particle‐tracking simulation. Our new method identifies a flaperon drift path far south of a previous isotope‐based reconstruction. We conclude with specific recommendations for using our method to continue the search for MH370 and other applications.

Plain Language Summary

More than 8 years ago, on 8 March 2014, Malaysia Airlines Flight 370 departed from Kuala Lumpur, never to be seen again despite a 4‐year extensive search using sonar imaging technology, submersible vehicles, drift models, and other high‐tech methods. Pieces of plane debris were found across the Indian Ocean, with some confirmed to be of the missing plane. One of the MH370 flaperons, a part of the aircraft's wing, beached on Réunion Island with several generations of stalked barnacles attached to its surface, later identified as Lepas anatifera. At least some of the barnacles were attached and growing shortly after the crash. This study contributes the first experimentally derived equation relating oxygen isotope values of stalked barnacle L. anatifera shells to sea surface temperature during shell formation. We demonstrate how applying the new temperature‐δ ¹⁸O relationship to published data from small L. anatifera shells collected from the MH370 flaperon, combined with a novel particle‐tracking simulation method, can be used to reconstruct the latter part of the flaperon drift path before beaching. This same method could be applied to the largest, oldest barnacles collected from the same debris to provide important information about the debris drift origin and location of the missing plane.

Key Points

• First experimentally derived sea surface temperature‐δ ¹⁸O _shell equation for the stalked barnacle, Lepas anatifera

• New numerical modeling method for reconstructing debris drift paths and origins from barnacle δ ¹⁸O _shell data

• First application of these new tools to barnacle δ ¹⁸O _shell data from missing flight MH370 to produce a partial drift reconstruction