11:15
p.m.
I
have been monitoring the
La Palma quake swarm in the Canary Islands
closely for some time. It's time for an update with some
analysis.
The
threat of an Atlantic-wide
tsunami remains. The current status of the volcanic
eruption ALERT remains unchanged at
YELLOW - one
level under critical (RED).
The
swarm is continuing but at a slower pace than the previous
days. So far, this has been the largest swarm to strike the
island in terms of numbers of quakes and size of quakes. The
depth of the quakes has also been much more shallow (closer to
the surface) than previous swarms.
As
I indicated previously, the past patterns in run-ups to
volcanic eruptions show such swarms can continue steadily
toward an eruption, die out altogether, or see a resurgence
after a brief lull of hours or days. We've already seen a lull
that lasted about 3 hours, followed by a resurgence of quakes.
The
depth of the current swarm shows quakes are occurring in the
6-8 km (3.75-5 miles) range below the surface. Once magma
intrusions and associated quakes reach to within 5 km below
the surface, there is almost always an eruption that occurs
within hours or a few days. We are very close to that figure
now and I would suggest than an eruption is very likely to
occur in the next few days. With the amount of magma coming
into the system, it seems likely the eruption whenever it
happens could be major.
As
I said before, there are a lot of "if's" in the equation that
makes predicting a volcanic eruption extremely difficult. I
have successfully predicted a handful of other eruptions in
the past, including very large eruptions, but there are no
guarantees I will be able to do so with
La Palma. So, we watch and wait.
I
would expect to see a quickened pace of quakes, like a woman's
contractions in labor just before she gives birth. I would
also expect to see the quakes rising to shallower depths just
ahead of an eruption.
I
would expect to see a major earthquake at the time of the
eruption. I'm watching for something in the
M6.4-7.2 range if there is a major eruption. The
situation can rapidly change in just a few hours, so it is
hard to stay on top of what is happening when you work full
time as I do and have only momentary opportunities to check in
on what is happening.
If
there is a large eruption, then what we watch for is to see if
the west flank where the quakes are happening breaks off into
the ocean as scientists have speculated. If it goes off more
or less as one big chunk then a mega-tsunami will occur and
all Atlantic-coastal regions will be affected, including the
east coast of the
U.S. where tsunami waves will strike within 7-9 hours.
Wave height estimates suggest waves could be anywhere from
85-100 ft. on the conservative side, or up to 300 ft. or more
on the other end of the speculation spectrum. If that occurs,
Florida would be the worst affected of all states,
being completely inundated, due to its low elevation and
flatness.
There
is another angle on all this as well. Past precedents suggest
that while theoretically possible, it would be unlikely for
one huge chunk of the island to fall into the ocean in one big
piece. It would more likely be like a landslide where rocks
crumble and there are successive stages of multiple "slides"
into the ocean that occur over time - NOT all at once in one
"shot." While the total volume of rock may be the same, this
scenario could rule out a tsunami completely crossing the
Atlantic with such high waves as are being predicted by
scientists. A local tsunami would occur affecting areas within
1,200-1,500 miles or so, but not likely an ocean-wide
mega-tsunami. It would still be quite devastating in western Africa,
western
Mediterranean, the Azores, and the U.K.,
but not as bad or far-reaching as the original "scientific
speculation."
There
are many factors at play here that will affect the ultimate
outcome. Will the volcano erupt at this time? If so, how high
a magnitude will the eruption quake reach? How explosive will
the eruption be? Will it be big enough to cause the island to
split? How large a volume of rock will be pushed into the sea?
Will it occur in one big chunk? Or will it come off in
successive stages over several hours or days? If a tsunami
reaches the U.S. coast, how high will the waves be?
How far inland could they reach?
No
human can answer all these questions with absolute accuracy
BEFORE the events occur. One can only look at best case and
worst case scenarios as I have tried to do in this brief
analysis, providing you with an informed opinion. I do not
claim to be an expert in volcanic eruptions, but I do have
some knowledge on the subject and have a fairly accurate track
record with eruptions over the past few years.
I
do think if you live in coastal areas of the Atlantic that you
should be on
ALERT and prepared to evacuate at a moment's notice.
Feel
free to reply with your thoughts and comments.
Keeping
You Informed!
The
Watchman