Race to unravel mystery of 1908 Tunguska catastrophe - the world’s biggest explosion

Lakes may hold the answer to the epic Tunguska Event, an atmospheric explosion 112 years ago which had the force of 185 Hiroshima bombs, wiping out 80 million trees.

Sediments are seen as the key to understanding an event that - because of its remote location - was not easily investigated at the time. 

A meteor is believed to have burst some 5 to 10 kilometres above the Earth's surface, flattening more than 2,000 square kilometres (770 square miles) while causing no known casualties. 

Now scientists from four major institutes - Novosibirsk Institute of Nuclear Physics, Novosibirsk Institute of Geology and Mineralogy, Tunguska Nature Reserve and Krasnoyarsk Biophysics Institute - are actively studying traces of the last century’s catastrophe hoping to understand an event that literally shook the world. 

‘The mystery of the Tunguska Catastrophe worries both the scientists and the public’, said Dr Arthur Meidus, deputy director to Tunguska Nature Reserve. 

‘The meteorite is not here as a physical body, but the traces of the extremely powerful explosion are, which is what is currently studied by researchers. 

‘Many of us still hope to unravel the scenario of 1908 disaster.’

How, specifically? 

Take remote Lake Zapovednoye, some 40 km from the supposed epicentre of the aerial explosion. 

'Although this lake is outside the territory that was affected in 1908, it is of great interest,’ said Dr Meidus.

'It is deep, and silty sediments, that have accumulated here, do not mix, or subside.’

In other words they ‘contain information from earlier years’. 

This includes the ‘history of non-stop climate changes and catastrophic events’.

He said: ‘Spring-autumn waste waters and the Lakura River brought traces of the Tunguska catastrophe to this lake, because the event was accompanied by massive wildfires and emissions of both planet and space origin.’

Experiments with the use of modern methods of microanalysis, such as X-ray fluorescence (XRF) analysis deploying synchrotron radiation, show the possibility of a search for micro particles of extraterrestrial origin in dated layers of the sediments.

He said: 'We discovered a distinguishing light-coloured layer in sediments of Lake Zapovednoye the content of which - an increased content of potassium, titanium, rubidium, yttrium, and zirconium - allows to tie it to the consequences of the Tunguska bolide explosion.

'This way we know which layer of sediments might contain particles of extraterrestrial origin.

'We established the indicators, that is search criteria, during work with samples of the Chelyabinsk and Sikhote-Alin meteorites.

‘The next stage implies search for micro-particles with unusual composition with the use of synchrotron radiation.

'Now we know where to look for them.

‘If there is extraterrestrial substance, it will be in the 1908-1910 layer.' 

Other research into Tunguska is underway, too. 

For example, Italian scientists carried out research over 21 years which claimed the dazzling blue-water of Lake Cheko fills the 'missing' impact crater, so giving the elusive evidence that this phenomenon was caused by the meteorite.

Russian geologists have strongly disputed this claim, insisting there is no impact crater because the meteor was entirely destroyed in the atmosphere. 

Except perhaps for a few traces in the sediment of Zapovednoye and other lakes.