Sperm whale strandings have been documented along the coastlines of the North Sea since the Middle Ages, but the cause has remained an elusive mystery. However, researchers studying the possible connection between a mass whale stranding in early 2016 – during which 29 sperm whales were found beached on the coasts of Germany, the Netherlands, the UK and France – and two major solar storms that took place at the very end of December in 2015 and produced huge displays of the Aurora Borealis, may have an answer.
They argue that sperm whales navigate using the variations in the strength of Earth’s geomagnetic field in different locations, ‘reading’ these anomalies in the same way humans read contours on maps. Researcher Dr Klaus Vanselow and his colleagues say that large-scale solar storms distort the magnetic field, causing whales to ‘read’ the map wrong and travel in the wrong direction.
Looking specifically at the region around Shetland, the scientists found that these solar events would have caused short-term shifts in the magnetic field of up to 460km, in the area between the islands and Norway. This could have caused sperm whales in the region to move in the wrong direction.
They also believe that sperm whales see a regular magnetic anomaly off the Norwegian coast as a “geomagnetic mountain chain”, a kind of guardrail that prevents them from entering the North Sea.
The solar storms may have nullified this effect, rendering the mountain chain invisible and allowing the whales to swim through into the North Sea.
Interestingly, NASA researchers have also been investigating the question of whether solar storms can affect “a whole range of cetaceans around the world”, and will shortly publish a paper on a similar topic, examining the connection between geomagnetic storms and strandings in Cape Cod.