On the morning of July 2nd, 2023, a new volcanic eruption began on a highly populated island
of France which is home to more than 850,000 people.
This eruption occurred at the Piton de la Fournaise volcano, where two fissures of lava
emerged on its flanks, ejecting bombs of lava into the air to a height of 50 meters or 164
feet.
For context, the Piton de la Fournaise shield volcano encompasses the eastern two fifths
of the island of Reunion which is itself 760 kilometers east of Madagascar's eastern coastline.
The eruption on the morning of July 2nd was preceded by what is known as a "seismic crisis"
at 7:36 am local time.
These seismic crises occur at Piton de la Fournaise when its shallow magma chamber fills
to such an extent with magma that it essentially becomes full.
Yet, magma still continues to push into this region, causing pressure to build.
This presure then reaches such an extent that it causes overlying rock to fracture, generating
earthquakes.
In this case, magma was rapidly moving towards the surface, resulting in more than 1100 earthquakes
in a 24 hour timespan, and all of this was correctly predicted to erupt on the volcano's
eastern flank which began at 8:30 am local time.
The fissure formed with more than a dozen small vents erupting simultaneously along
a chain of activity approximately 820 meters east of the summit crater rim of Piton de
la Fournaise.
This 1,000 meter long fissure stretched from approximately 2160 meters elevation to 1800
meters above sea level.
The maximum amount of magma effusion occurred early on, generating the highest lava fountains,
as this was also when the eruption was most volatile rich.
Lava from this fissure was erupting at a fairly slow rate, likely a little less than 10 cubic
meters per second, forming ropey pahoehoe lava which did not move very fast.
Despite this fact, lava has already advanced in a two pronged flow with the northern lobe
having moved 900 meters and the southern lobe having moved 1500 meters.
This lava slowly continued to advance towards the east as this represented lower elevation,
but then, volcanic tremor at the volcano once again increased.
Suddenly, at 5:50 pm local time, a second eruptive fissure formed, but this time on
the southeast flank of the volcano.
These fissures are now both emitting molten rock which if it continues to flow for a long
enough period could in a few days to weeks time eventually reach a major road on the
eastern section of the island.
In the past 23 years, lava flows have covered sections of this road on 5 occasions before
entering the ocean and adding new land to the island, with the last example occurring
in 2010.
However, as of the writing of this video, these roads are not yet in imminent danger.
Regardless, visitation of the Piton de la Fournaise volcano is prohibited for the time
being as new fissures could form or expand with little or no warning beforehand.
This eruption could last anywhere from less than 72 hours to more than a year in length,
although most eruptions of this shield volcano which is one of the planet's most active alongside
Kilauea generally last around a month to a month and a half.
If you are wondering why the western flank of Piton de la Fournaise has such deep ravines
in a semicircular like shape, the reason is that they represent three collapse calderas
of the volcano which date to 250,000 years ago, 65,000 years ago, and 2,700 BCE.
The youngest caldera has since its formation caused 93% of this volcano's lava to flow
to the east along a set path.
Flank eruptions outside of this caldera have occurred, with the most recent example occurring
in 1998, but there are not currently any indications that this will occur.
As a result, for now, no homes or structures are at risk in this primarily effusive volcanic
eruption.
Thanks for watching!
If you would like to request a specific topic, please leave a comment below.
Additionally, I would like to thank this channel's patrons on Patreon and channel members on
YouTube!