El sitio web
Signs of the Times (sott.net) recopila, mes a mes, unos 20 minutos de videos
mostrando los acontecimientos climáticos y tectónicos más
resonantes de los últimos 30 días en todo el planeta. En los últimos meses las
imágenes son, para decir algo, ligeramente apocalípticas.
Primero fíjense
en el último video, para que vean que no exagero:
https://www.sott.net/article/319812-SOTT-Earth-Changes-Summary-May-2016-Extreme-Weather-Planetary-Upheaval-Meteor-Fireballs
Ahora bien, uno
se pregunta: ¿existe alguna relación entre el proceso de calentamiento global
en curso y los eventos corticales (aparentemente, cada vez más frecuentes) de
deslizamientos de tierras, activación de fallas, aparición de “sinkholes”
(agujeros en la tierra), erupciones volcánicas e incluso terremotos? Bill
McGuire es profesor de Peligros climáticos y Geofísicos del University College
de Londres. Hace algo más de cuatro años (Febrero de 2012) escribió la nota que
sigue para el diario británico The Guardian.
Título: Climate
change will shake the Earth
Subtítulo: A
changing climate isn't just about floods, droughts and heatwaves. It brings
erupting volcanoes and catastrophic earthquakes too
Texto: The idea
that a changing climate can persuade the ground to shake, volcanoes to rumble
and tsunamis to crash on to unsuspecting coastlines seems, at first, to be
bordering on the insane. How can what happens in the thin envelope of gas that
shrouds and protects our world possibly influence the potentially Earth-shattering
processes that operate deep beneath the surface? The fact that it does reflects
a failure of our imagination and a limited understanding of the manner in which
the different physical components of our planet – the atmosphere, the oceans,
and the solid Earth, or geosphere – intertwine and interact.
If we think about
climate change at all, most of us do so in a very simplistic way: so, the
weather might get a bit warmer; floods and droughts may become more of a
problem and sea levels will slowly creep upwards. Evidence reveals, however,
that our planet is an almost unimaginably complicated beast, which reacts to a
dramatically changing climate in all manner of different ways; a few – like the
aforementioned – straightforward and predictable; some surprising and others
downright implausible. Into the latter category fall the manifold responses of
the geosphere.
The world we
inhabit has an outer rind that is extraordinarily sensitive to change. While
the Earth's crust may seem safe and secure, the geological calamities that
happen with alarming regularity confirm that this is not the case. Here in the
UK, we only have to go back a couple years to April 2010, when the word on
everyone's lips was Eyjafjallajökull – the ice-covered Icelandic volcano that
brought UK and European air traffic to a grinding halt. Less than a year ago,
our planet's ability to shock and awe headed the news once again as the east
coast of Japan was bludgeoned by a cataclysmic combination of megaquake and
tsunami, resulting – at a quarter of a trillion dollars or so – in the biggest
natural-catastrophe bill ever.
In the light of
such events, it somehow seems appropriate to imagine the Earth beneath our feet
as a slumbering giant that tosses and turns periodically in response to various
pokes and prods. Mostly, these are supplied by the stresses and strains
associated with the eternal dance of a dozen or so rocky tectonic plates across
the face of our world; a sedate waltz that proceeds at about the speed that
fingernails grow. Changes in the environment too, however, have a key role to
play in waking the giant, as growing numbers of geological studies targeting
our post-ice age world have disclosed.
Between about
20,000 and 5,000 years ago, our planet underwent an astonishing climatic
transformation. Over the course of this period, it flipped from the frigid
wasteland of deepest and darkest ice age to the – broadly speaking – balmy,
temperate world upon which our civilisation has developed and thrived. During
this extraordinarily dynamic episode, as the immense ice sheets melted and
colossal volumes of water were decanted back into the oceans, the pressures
acting on the solid Earth also underwent massive change. In response, the crust
bounced and bent, rocking our planet with a resurgence in volcanic activity, a
proliferation of seismic shocks and burgeoning giant landslides.
The most
spectacular geological effects were reserved for high latitudes. Here, the
crust across much of northern Europe and North America had been forced down by
hundreds of metres and held at bay for tens of thousands of years beneath the
weight of sheets of ice 20 times thicker than the height of the London Eye. As
the ice dissipated in soaring temperatures, the crust popped back up like a
coiled spring released, at the same time tearing open major faults and
triggering great earthquakes in places where they are unheard of today. Even
now, the crust underpinning those parts of Europe and North America formerly
imprisoned beneath the great continental ice sheets continues to rise – albeit
at a far more sedate rate.
As last year's
events in Japan most ably demonstrated, when the ground shakes violently
beneath the sea, a tsunami may not be far behind. These unstoppable walls of
water are hardly a surprise when they happen within the so-called ring of fire
that encompasses the Pacific basin but in the more tectonically benign North
Atlantic their manifestation could reasonably be regarded as a bit of a shock.
Nonetheless, there is plenty of good, hard evidence that this was the case
during post-glacial times. Trapped within the thick layers of peat that pass
for soil on Shetland – the UK's northernmost outpost – are intrusions of sand
that testify to the inland penetration of three tsunamis during the last 10,000
years.
Volcanic blasts
too can be added to the portfolio of postglacial geological pandemonium; the
warming climate being greeted by an unprecedented fiery outburst that wracked
Iceland as its frozen carapace dwindled, and against which the recent ashy
ejaculation from the island's most unpronounceable volcano pales.
The huge
environmental changes that accompanied the rapid post-glacial warming of our
world were not confined to the top and bottom of the planet. All that meltwater
had to go somewhere, and as the ice sheets dwindled, so the oceans grew. An
astounding 52m cubic kilometres of water was sucked from the oceans to form the
ice sheets, causing sea levels to plummet by about 130 metres – the height of
the Wembley stadium arch. As the ice sheets melted so this gigantic volume of
water was returned, bending the crust around the margins of the ocean basins
under the enormous added weight, and provoking volcanoes in the vicinity to
erupt and faults to rupture, bringing geological mayhem to regions remote from
the ice's polar fastnesses.
The breathtaking
response of the geosphere as the great ice sheets crumbled might be considered
as providing little more than an intriguing insight into the prehistoric
workings of our world, were it not for the fact that our planet is once again
in the throes an extraordinary climatic transformation – this time brought
about by human activities. Clearly, the Earth of the early 21st century bears
little resemblance to the frozen world of 20,000 years ago. Today, there are no
great continental ice sheets to dispose of, while the ocean basins are already
pretty much topped up. On the other hand, climate change projections repeatedly
support the thesis that global average temperatures could rise at least as
rapidly in the course of the next century or so as during post-glacial times,
reaching levels at high latitudes capable of driving catastrophic breakup of
polar ice sheets as thick as those that once covered much of Europe and North
America. Could it be then, that if we continue to allow greenhouse gas
emissions to rise unchecked and fuel serious warming, our planet's crust will
begin to toss and turn once again?
The signs are
that this is already happening. In the detached US state of Alaska, where
climate change has propelled temperatures upwards by more than 3C in the last
half century, the glaciers are melting at a staggering rate, some losing up to
1km in thickness in the last 100 years. The reduction in weight on the crust
beneath is allowing faults contained therein to slide more easily, promoting
increased earthquake activity in recent decades. The permafrost that helps hold
the state's mountain peaks together is also thawing rapidly, leading to a rise
in the number of giant rock and ice avalanches. In fact, in mountainous areas
around the world, landslide activity is on the up; a reaction both to a general
ramping-up of global temperatures and to the increasingly frequent summer
heatwaves.
Whether or not
Alaska proves to be the "canary in the cage" – the geological
shenanigans there heralding far worse to come – depends largely upon the degree
to which we are successful in reducing the ballooning greenhouse gas burden
arising from our civilisation's increasingly polluting activities, thereby
keeping rising global temperatures to a couple of degrees centigrade at most.
So far, it has to be said, there is little cause for optimism, emissions
rocketing by almost 6% in 2010 when the world economy continued to bump along
the bottom. Furthermore, the failure to make any real progress on emissions
control at last December's Durban climate conference ensures that the outlook
is bleak. Our response to accelerating climate change continues to be
consistently asymmetric, in the sense that it is far below the level that the
science says is needed if we are to have any chance of avoiding the
all-pervasive devastating consequences.
So what –
geologically speaking – can we look forward to if we continue to pump out
greenhouse gases at the current hell-for-leather rate? With resulting global
average temperatures likely to be several degrees higher by this century's end,
we could almost certainly say an eventual goodbye to the Greenland ice sheet,
and probably that covering West Antarctica too, committing us – ultimately – to
a 10-metre or more hike in sea levels.
GPS measurements
reveal that the crust beneath the Greenland ice sheet is already rebounding in
response to rapid melting, providing the potential – according to researchers –
for future earthquakes, as faults beneath the ice are relieved of their
confining load. The possibility exists that these could trigger submarine
landslides spawning tsunamis capable of threatening North Atlantic coastlines.
Eastern Iceland is bouncing back too as its Vatnajökull ice cap fades away.
When and if it vanishes entirely, new research predicts a lively response from
the volcanoes currently residing beneath. A dramatic elevation in landslide
activity would be inevitable in the Andes, Himalayas, European Alps and
elsewhere, as the ice and permafrost that sustains many mountain faces melts
and thaws.
Across the world,
as sea levels climb remorselessly, the load-related bending of the crust around
the margins of the ocean basins might – in time – act to sufficiently
"unclamp" coastal faults such as California's San Andreas, allowing
them to move more easily; at the same time acting to squeeze magma out of
susceptible volcanoes that are primed and ready to blow.
The bottom line
is that through our climate-changing activities we are loading the dice in
favour of escalating geological havoc at a time when we can most do without it.
Unless there is a dramatic and completely unexpected turnaround in the way in
which the human race manages itself and the planet, then long-term prospects
for our civilisation look increasingly grim. At a time when an additional
220,000 people are lining up at the global soup kitchen each and every night;
when energy, water and food resources are coming under ever-growing pressure,
and when the debilitating effects of anthropogenic climate change are
insinuating themselves increasingly into every nook and cranny of our world and
our lives, the last thing we need is for the dozing subterranean giant to
awaken.
Acabo de ver esto:
ResponderEliminarhttps://www.rt.com/news/346224-co2-stored-underground-stone/?utm_source=rss&utm_medium=rss&utm_campaign=RSS
Si, hace un tiempo se viene hablando de la posible reutilización de pozos en el sepultamiento del CO2. No tengo gran idea del tema. Podría incluso ser un negocio colateral de los petroleros. habrá que ver. Cordiales saludos,
ResponderEliminarAstroboy