People near Igloolik, Nunavut, in the Canadian Arctic have reported a strange noise that seems to be coming from the sea floor.
The noise has been described as a ‘pinging’ sound.
It is thought to be keeping animals away from an area of water surrounded by ice.
The Canadian armed forces have sent a crew to check it out. They performed lots of different searches using scanning technology but they didn’t find anything unusual.
Various explanations for the sound have been put forward by the Canadian press:
* It a sonar survey conducted by a mining company
* It is being generated on purpose by Greenpeace to scare wildlife away from the rich hunting ground
* It is caused by military submarines
However, local mining companies insist they do not work in the area, Greenpeace has denied it is responsible and the military say no submarines – either domestic or foreign – are known to have operated in the area.
The cause of the pings, therefore, remains a mystery.