In 1935, Mauna Loa in Hawaii erupted, sending a slow moving lava flow towards the densely
populated town of Hilo.
After it became clear that the lava was going to reach the town, some attempts were made
at diverting the lava flow.
These attempts at diverting this lava were done in vain until an idea was proposed which
was so wacky…that it could actually work.
The wacky idea was to bomb the volcano.
A series of 10 US army biplanes set off from a local military base and flew over a series
of active lava tubes which were supplying the growing lava flow downslope.
Then, at a low altitude over the advancing lava flows dropped twenty 600 pound MK 1 demolition
bombs over the active lava tubes supplying molten rock downslope.
At first, not much happened.
Then, 6 days later, the advancing lava flows stopped, thus sparing the town and its water
supply.
So, why did this work?
This video will discuss this unusual strategy, which can indeed divert lava flows given a
very specific set of circumstances.
Over the course of several thousand years, humans have long attempted to divert slow
moving lava flows, which varying degrees of success.
The most common method is building earthen walls to create a barrier, thus causing the
lava to move around it.
However, none of these methods are truly that effective.
They typically fail but are still better than doing nothing, because they on rare occasions
succeed.
In the case of bombing a volcano, success is also quite rare.
The reason behind bombing a volcano is to hit a very specific part of an advancing lava
flow, termed a lava tube.
Lava tubes are underground rivers of molten rock which supply lava to more distant locations.
They can range in size from only a few dozen meters to several kilometers in length.
Without them, a volcano would only be able to cover a limited extent around the active
vents with material.
Thus, if you were to break a lava tube and cause a blockage, it would decrease the amount
of molten rock supplied downslope.
In truly ideal circumstances, this could even cause lava to erupt onto the surface above
the blockage, and cause the entire flow of lava to be redirected to a desired location!
On a few rare historical occasions, this worked perfectly.
As an example, in May of 1992, Mount Etna produced a large flank eruption, sending slow
moving lava flows towards a highly populated area.
A group of engineers were then sent up the mountain to a steep hillside containing an
active lava tube.
On foot, they broke holes in the lava tube, and carefully planted explosives on the side
to cause a blowout.
In total, 7700 kilograms of high explosives were placed, after which the engineers left
the area.
Then, from a safe distance, they detonated the explosives.
Due to the very precise series of explosions, a near total blockage soon formed.
Lava then spilled to the side into a series of artificial lava channels which had been
constructed in the years beforehand.
This lava flow went harmlessly into an unpopulated area, thus saving the town.
Thus, if you are an authority figure and are facing a slow moving lava flow moving rapidly
towards you, bombing a volcano can work given a set of very specific criteria which must
be followed before carrying out this option.
First, the advancing lava flow needs to have a composition of basalt or basaltic andesite,
meaning that it is quite fluid and has a low silica content.
Next, there must be lava tubes present in the ongoing eruption.
Third, a steep slope is needed adjacent to the active lava tube, as gentle slopes reduce
your chance of success.
That hillside must redirect towards a completely unpopulated area, or at least an area with
fewer structures.
Fourth, the area you plant explosives must not be filled with structures.
A strong blast could cause more damage to nearby structures than a lava flow.
In the case of the ongoing eruption of La Palma, a politician suggested bombing a lava
flow.
In the case of that eruption, this is a horrible idea because the blast would damage nearby
homes and there is nowhere truly harmless to redirect the lava into.
I hope that you enjoyed this video!
If you would like to request a specific topic, please leave a comment below!
Additionally, if you wish to support this channel, consider becoming a patron on patreon.