Especially relevant after the earthquakes in Mexico coinciding with hurricanes in the Caribbean
Witten in 2015 in the days before Robertscribbler wrote about more than electric cars and before he ignored some of the more dire indications
Climate Change’s ‘Waking Giant’ to Set off Rash of Volcanic Eruptions, Tsunamis, Earthquakes?
(Last
week’s Calbuco eruption in Chile spews massive cloud of ash and
sets off a fireworks display of volcanic lightning. Image
source: IFLScience.)
28
April, 2015
If
you look at the geological record of the end of the last ice age,
there’s something that crops up that’s more than a little bit
disturbing. The approximate 10,000 year period in which 4 degrees
Celsius of warming took place was also punctuated by a rash of
intense volcanic activity, earthquakes and tsunamis.
It
was a time of extraordinary geophysical changes that not only saw
the, sometimes catastrophic, melting of massive ice sheets and
extreme rises in sea level — it also saw severe geological
upheaval. In one region alone — Iceland — instances
of volcanic eruption increased 30-50 fold during a period starting
about 12,000 years ago.
Overall, global spikes in volcanism began near the start of major
melt events at around 18,000 years ago and continued on through the
Iceland spike at the 12,000 year time-frame, finally tapering off
around 7,000 years ago. In
the 12,000 to 7,000 year before present period, global volcanic
activity was between 2 and 6 times today’s frequency.
(A
2010 study found large spikes in volcanic activity at a number of
Iceland volcanoes at the end of the last ice age. Image source: How
Will Melting of Ice Affect Volcanic Hazards in the 21st Century?)
Geologically
active regions around the world and especially in close proximity to
melting ice and rising seas saw much greater volcanic eruption,
earthquake and tsunami frequency. In particular, California, Europe,
and Iceland saw intense volcanic activity spikes. A set of past
events pointing toward 21rst Century risks explored in the
book: Waking
the Giant — How Climate Change Triggers Earthquakes, Volcanoes and
Tsunamis.
A
leading theory, presented by Dr. Bill McGuire, Hugh Tuffin, J.
Maclennan, Peter Huybers and many others is that changes in stress to
the Earth’s crust caused by the loss of billions of tons of mass by
ice sheets and the displacement of those billions of tons into the
world’s ocean system spurred previously stable magma systems into a
chaotic displacement. In addition, direct melting of glaciers on
slope systems, rising seas and even changes in flood frequency at
individual volcanoes, faults and zones of steep topography can result
in heightened rates of eruption, earthquakes and instances of slope
collapse.
This
evidence is causing scientists to investigate feedbacks
between warming and potential increases in volcanic activity,
earthquakes and tsunamis. A set of events that may also risk the
destabilization of undersea methane hydrate stores through the slope
collapse and enhanced magma heating mechanisms as well.
Current
Events, Raging Pace of Human Warming Bring old Concerns to Light
Though
this line of research isn’t new — with modern studies stretching
back to the 1950s and with end ice age upheaval research extending
for nearly two centuries — recent events have served to underline
old concerns. In 2013, the massive eruptions of Iceland’s volcanoes
and related disruption of European air travel brought voices like
those of Dr. Bill McGuire again to the fore. And, more recently, the
massive Tibetan earthquake of this past weekend, resulting in the
loss of 4,000 lives, has called into question current human climate
change’s role in geological upheaval events.
(Dust
flies through the air during the initial moments of last weekend’s
catastrophic Tibet Earthquake. Image source: RT
News.)
Evidence from the end of the last Ice Age has already shown that the planet’s uneasy web of seismic faults – cracks in the crust like the one that runs along the Himalayas – are very sensitive to the small pressure changes brought by change in the climate. And a sensitive volcano or seismic faultline is a very dangerous one.
Though
the Tibetan earthquake was going to happen at some time, it is
possible that changes in ice loading on Himalayan glaciers, changes
in water volume outflows in the annual Asian monsoon, and sea level
rise adding pressure to the geological plates below coastlines —
especially in low-lying Bangladesh — had an impact. Such stresses
can increase magma chamber production or trigger fault lines to
release.
McGuire
notes in Newsweek:
Climate change may play a critical role in triggering certain faults in certain places where they could kill a hell of a lot of people. These stress or strain variations – just the pressure of a handshake in geological terms – are perfectly capable of triggering a quake if that fault is ready to go (emphasis added).
One
example of where relatively small changes to geological stress can
have a big impact on volcanic activity is the Pavlov volcano in
Alaska. As McGuire describes, this volcano only erupts during Autumn
and Winter. At that time storms ride up into a nearby ocean zone,
pushing an average 10cm or 15cm rise in sea level. The added weight
of the water is enough to torque the crust and push magma out. Now
imagine the kind of extra volcanic activity that could result from 1,
6, or 250 feet of global sea level rise under the raging rate of
human-caused warming and you begin to understand the concern.
So
the question that many geologists are asking is this: will the
greatly exaggerated spike of human warming and related extreme pace
of glacial melt, sea level rise, and rainfall changes also result in
a greatly exaggerated spike in volcanism, earthquakes, and tsunami
events?
Fault
lines around the world will be under increased and ever-changing
stress. Volcanoes around the world will see the same. The great Ring
of Fire is in an ocean-spanning zone. Many, many volcanic, fault and
slope systems encompassed in its arc will feel the added weight of
sea level rise caused by human warming. In addition, as much or more
than the 4 degrees Celsius worth of warming achieved at the end of
the last ice age could be seen by the end of this Century.
It’s
that kind of very rapid pace of change that has geologists worried
with more than a handful thinking that the catastrophic geophysical
changes may have already started.
Links:
Hat
Tip to Colorado Bob
No comments:
Post a Comment
Note: only a member of this blog may post a comment.