© GettyThe new analysis, which points to a layer of slime as the reason for submarine landslides, has the potential to flag up safety risks associated with oceanic endeavors (file photo)
Scientists have finally learned of a potential cause for submarine landslides, according to a new report from the Helmholtz Centre for Ocean Research Kiel.
The cause for the landslides - that are often much more destructive than those on the shore - was previously a mystery.
But researchers combined seismic data with sea floor samples collected by the Ocean Drilling Program to deduce that a slime left behind by microalgae might be causing the potentially disastrous shifts in the earth's crust.
Comment: It's likely there are greater triggers for these shifts than this layer of slime: Scientists predict upsurge in major earthquakes for 2018 due to slowdown in Earth's rotation
The report, published in research journal Geology, explained how landslides in the ocean are of a different scale than those on land.
It said: 'When the seabed loses its stability and starts to move, it often happens in much larger dimensions than landslides ashore - and at slopes with very low gradients.'
Study author Dr Morelia Urlaub explained: 'Submarine landslides happen on very shallow slopes, often with gradients as low as one or one-and-a-half degrees.'
But much damage can be done even when a landslide occurs on a fairly flat surface, the report explained.
'Displacement of large amounts of sediment under water can cause devastating tsunamis.'
Before now scientists knew very little about why submarine landslides occurred, but the new research marks a step toward figuring out what causes them.
The ability to predict these landslides, which could stem from the new report, has the potential to help map out the safety risks of offshore endeavors.
The report said: 'Searching for the causes of such landslides is much more difficult underwater than on land due to their inaccessibility.'
Additionally, the report clarified that researchers still do not fully know why the landslides happen. It stated: 'Why and when submarine landslides develop is hardly understood.
But, it said, 'the outcome of this study may help to identify areas which are prone to landslides.'
The team from the Helmholtz Centre referenced two submarine landslides in the new report. One took place 8,150 years ago and displaced an area of the sea floor that is larger than Scotland.
It resulted in a tsunami that was up to 65.6 feet tall, which hit Norway and the Shetland Islands particularly hard.
Comment: Within that time frame great changes had been occurring on our planet which may provide a clue as to its possible cause: Of Flash Frozen Mammoths and Cosmic Catastrophes
It is referred to as the Storegga landslide, and the researchers said it could have taken place up to 6,561 feet below sea level.
'The Storegga landslide affected an area larger than Scotland, and the material today covers hundreds of kilometers on the seabed,' the report said.
But the data analyzed for the new study was based on a submarine landslide that took place off the coast of Mauritania in Northwest Africa.
'[The researchers] combined results from drilling with seismic data and were able to show that a certain stratification of the seafloor was responsible for at least one slide in this region,' the report said.
The slope of the area affected by the Storegga landslide was just 1.6 degrees, but the landslide off the Mauritanian coast had a slope that was, at most, 2.8 degrees.
The report explained the logistics of a submarine landslide.
It said: 'When a layer gives way, all overlying layers move down the slope.
'It is difficult to determine the composition of this particular layer because it is destroyed with the landslide.'
This conundrum has kept researchers from understanding the causes of underwater landslides until now.
But Dr Urlaub's team was able to develop research based on sea floor samples and seismic data to come up with the new theory.
In the case of the landslide near Northwest Africa, portions of the slope involved in the shift were still intact. This allowed Dr Urlaub to analyze the exact composition of the sediment at the scene.
'We were able to use these old 1980s cores to look for the weak point in the slope,' she explained.
'The combination of this drilling and seismic data showed that the slope was slipping just where a clay layer overlies ooze made up of the remains of fossil planktonic organisms,' the report said.
The ooze the researchers analyzed mainly consisted of diatoms, microalgae that are some of the most common categories of phytoplankton.
The scientists ultimately learned that the ooze allowed for the eventual collapse of the sea floor.
It explained: 'These phytoplankton organisms form shells out of silica. In some phases of the earth's history, large amounts of diatoms form, the shells of which, after dying, sink to the bottom of the sea and form thick layers.
'Since diatomaceous oozes appear to be a common feature off the Northwest African coast as observed in seismic data, the authors assume that this phenomenon is also the reason for other mega-slides in the region.'
The research is the first of its kind to suggest ooze as a possible answer to the cause of oceanic landslides.
Comment: While this slime may contribute to landslides, its likely there is a greater trigger. What we can take away from this study is that areas situated near or on top of this slime could be very vulnerable indeed. Particularly with all the activity we're seeing on our planet these days, see: SOTT Earth Changes Summary - January 2018: Extreme Weather, Planetary Upheaval, Meteor Fireballs
WHAT CAUSES TSUNAMIS?
A tsunami, sometimes called a tidal wave or a seismic sea wave, is a series of giant waves that are created by a disturbance in the ocean.
The disturbance could be a landslide, a volcanic eruption, an earthquake or a meteorite; the culprit is most often an earthquake.
If the landslide or earthquake triggering the tsunami occurs nearby the shore, inhabitants could see its effects almost immediately.
The first wave of the tsunami can arrive within minutes, before a government or other institution has time to issue a warning.
Areas that are closer to sea level have a higher risk of being affected by the waves.
Those less than 25 feet from sea level are the most dangerous.
The cause of death most frequently associated with tsunamis is drowning. Additional hazards include drinking water contamination, fires and flooding.
Initial tsunami warnings are usually based on seismic information only.
Inhabitants of coastal areas that might be exposed to a tsunami are encouraged to follow evacuation routes in the event that they receive a tsunami warning.
They should seek higher ground or move inland immediately to get away from the ocean.
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