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Rapid Sea Level Rise Possible as Ocean Floods into Antarctica at up to 400 Meters Per Year

From west to east and in a growing number of places, a warming ocean is cutting its way deep into Antarctica. Grounding lines — the bases upon which mile-high glaciers come to rest as they meet the water — are in rapid retreat. And this ocean, heated by human fossil fuel burning, is beginning to flood chasms that tunnel for hundreds of miles beneath great mountains of ice.

Such an immense flood has the effect of speeding up glaciers as far away as 500 miles from the point of invasion. It does this by generating a kind of abyssal pit that the glacier more swiftly falls into. And as these watery pits widen, they risk pumping sea level rise to catastrophic levels of ten feet or more by the end of this Century.

(A new study in Nature is the first to survey the rate of grounding line movement around Antarctica’s entire perimeter. What it found was disturbing. A large number of major glaciers are seeing historically rapid rates of grounding line retreat [red arrows] as only a few glaciers show very slow rates of grounding line advance [blue arrows]. Image source: Hannes Konrad et al, Nature, University of Leeds.)

The great ocean invasion is clearly on the march. Not yet proceeding everywhere, the advance is happening in enough places to cause major worry. In West Antarctica, 22 percent of its glaciers are seeing their grounding lines move inland by more than 25 meters per year. In the Antarctic Peninsula, 10 percent of glaciers are experiencing this retreat. And in East Antarctica, where the ice is piled thickest, 3 percent of glaciers are affected by the swift invasion.

The most rapid retreat — at up to 400 meters per year — is presently happening at Thwaites Glacier in West Antarctica. Thwaites alone encompasses enough ice to lift the world’s oceans by 3 meters. And the rate of inland ocean water invasion at this single location is a very serious concern.

(Grounding line retreat is just one of many factors that increase the risk of rapid sea level rise. Ice cliff instability, increased rainfall over glaciers, large floods of water into glaciers from melt ponds that then refreeze and fracture the ice, and a number of other factors all compound as the Earth is heated up by fossil fuel burning. Video source: International Business Times.)

But the issue is not one of single glaciers. It’s one where many very large mounds of ice all around Antarctica are under threat. And in much the same way that a dike risks breaking apart when it is punched through by a growing number of holes, Antarctica’s own flood gates to rapid sea level rise are threatened by each grounding line in quickening retreat. Another such ‘hole’ has formed at the Totten Glacier where the grounding line is retreating at around 150 to 175 meters per year. And Totten could produce another 3.4 meters of sea level rise if it collapsed into the Southern Ocean.

Continuing the dike anology, Antarctica holds back enough water as ice, in total, to lift the world’s ocean levels by an average of 200 feet. By greater or lesser degrees, each retreating glacier contains a portion of the potentially massive flood. And the overall rate of loss in the form of new glaciers going into retreat together with the pace of inland ocean invasion is speeding up.

This new set of research provides a more complete if fearsome picture of Antarctic melt. And though models aren’t yet able to pinpoint how fast sea level rise will be, a growing body of evidence points to greater than previously expected risk for rapid sea level rise this Century. So for the sake of our coastlines and of so many cities around the world, the time to act as swiftly as possible to reduce carbon emissions and their terrible related impacts is now.

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A Flood of Warm Water the Size of 30 Amazon Rivers is Melting One of East Antarctica’s Largest Glaciers

If we’ve learned anything this year, it’s that few of Antarctica’s submerged coastal glaciers are safe from the warming ocean. Places that we once thought wouldn’t be vulnerable to melt for decades or centuries are now starting to feel the heat of rising water temperatures.

The heat comes in the form of great floods of warmer than normal waters running beneath the ocean surface and then eating away at the undersides of ice shelves and sea fronting glaciers. These floods are provided by the warmth forced into the world ocean by rising global greenhouse gas concentrations. And such invasions are happening around Antarctica’s perimeter with increasing frequency. But perhaps the most disturbing such event now ongoing is the present warm water flood running in from the Southern Ocean toward East Antarctica’s Totten Glacier.

calving-front-of-the-totten-glacier

(The melting edge of the Totten Glacier. Image source: Antarctica.gov.)

Totten is a truly gigantic glacier. By itself representing an ice mass equal to that contained in all of West Antarctica’s many glaciers. If large sections of Totten and the associated Aurora Basin were to melt, seas could rise by 12 feet or more. During recent years, researchers identified a great canyon running between 2,000 and 3,600 feet below sea level and stretching six miles wide as a weak point for Totten — whose glaciers sit in an enormous, below sea level rift within East Antarctica.

Researchers recently found that the floating ice shelf buttressing Totten was melting from below. As of 2015, they hadn’t identified a mechanism for this melt. But they had a pretty short suspect list. This year, a new study led by Dr. Stephen Rich Rintoul found that a river of warm water flowing at a rate of 220,000 cubic meters per second was flooding into the vulnerable canyon entrance to Totten’s weak underbelly. The researchers determined that this volume of warm water — equaling a flow rate more than 30 times that of the Amazon River — was enough to account for the observed ice shelf losses over recent years in the range of 60 to 80 billion tons per year.

totten-glacier-basin

(The Totten Glacier of East Antarctica contains about as much ice mass as all of West Antarctica. Its catchment basin is roughly the size of the U.S. Southeast. Much of it sits below sea level. And an ice shelf buttressing the glacier’s largest outlet in a 6 mile wide and 3,600 foot deep canyon is rapidly melting. Once this ice shelf breaks apart, ocean water will flood inland along a reverse slope and the Totten Glacier will increase its rate of movement toward the ocean — significantly speeding rates of global sea level rise. Image source: Australian Antarctic Division.)

The study authors found that:

…several lines of evidence support the conclusion that rapid basal melt of the [Totten Ice Shelf] is driven by the flux of warm [modified circumpolar deep water] into the cavity: the presence of warm water at the ice front, the existence of a deep trough providing access of this warm water to the cavity, direct measurements of mass and heat transport into the cavity, the signature of glacial meltwater in the outflow, and exchange rates inferred from the heat budget and satellite-derived basal melt rates.

Presently, because the ice shelf floats, this melt is not adding to global sea level rise. But the shelf acts like a cork that’s stopping the rest of Totten from flowing into the ocean. And when the ice shelf weakens enough, it will rift and break apart — leaving the massive glaciers behind it exposed to the inrush of warm waters and removing the last major barrier preventing them from bursting out.

Links:

Ocean Heat Drives Rapid Basal Melt of Totten Ice Shelf

Scientists Confirm that Warm Ocean Water is Melting one of East Antarctica’s Biggest Glaciers

One by One, the Flood Gates of Antarctica are Breaking Open

Tottering Totten and the Coming Multi-meter Sea Level Rise

Antarctica.gov

Hat tip to Robert in New Orleans

One By One, the Flood Gates of Antarctica are Breaking Open

“We have still time to avoid the worst of it, but we have already opened a number of flood gates, one in West Antarctica, and several in Greenland.”Dr Eric Rignot.

“This kind of rifting behavior provides another mechanism for rapid retreat of these glaciers, adding to the probability that we may see significant collapse of West Antarctica in our lifetimes.” Ian Howat, Earth Sciences associate Professor at Ohio State University.

“Burning all the world’s coal, oil and gas would melt the entire Antarctic ice-sheet and cause the oceans to rise by over 50m, a transformation unprecedented in human history. The conclusion of a new scientific study shows that, over the course of centuries, land currently inhabited by a billion people would be lost below water.” — The Guardian.

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Massive Rift Forming in Larsen C

Larsen C. It’s the next big ice shelf on the butcher’s block in West Antarctica. And now it appears the shelf may be well on its way to facing the same fate as its companions Larsen A and Larsen B. That fate — disintegration and the ultimate release of glaciers that have been held in check for thousands of years into the world ocean.

It was only about 150 years ago that the Larsen Ice shelves were discovered. And the Larsen shelf system is thought to have been mostly stable throughout the last 12,000 years. But in 1995 Larsen A splintered into a million icebergs. And in 2002 the larger portion of Larsen B broke apart. Warming Ocean waters heated by an atmosphere loaded with greenhouse gasses did the damage. And now the same warm water currents that shattered Larsen A and Larsen B are endangering their larger cousin — Larsen C.

larsen-c-ice-rift

(Ice shelves and sea fronting glaciers serve as the flood gates keeping West Antarctica’s glaciers from spilling into the ocean and raising sea levels by as much as 20 feet. But warm ocean waters are causing these flood gates to melt and crack wide open. The above image shows a massive abyssal rift forming in the Larsen C ice shelf. A similar rift formed in the center of the Pine Island Glacier last year. A signal that the West Antarctic Ice Sheet could undergo a major collapse over the next 100 years. Image source: NASA.)

For today, a huge rift running through the ice shelf is about to break off a Delaware-sized iceberg into the Atlantic Ocean. The rift is broadening, deepening and extending. And it now measures 70 miles long, 300 feet wide, and a third of a mile deep. Once this enormous abyssal crack runs its course and causes about 10 percent of the ice shelf to break off, the big land-grounded glaciers sitting upon mountainous slopes behind the ice shelf will have less protection. They will increase their forward speed and contribute larger volumes of ice outflow to the growing problem of global sea level rise.

In this way, rifts in Antarctica’s sea fronting glaciers and ice shelves can be seen as giant cracks in the flood gates holding back enormous glaciers that, when released, will lift global sea levels by feet and meters.

Big Crack in the Pine Island Glacier

Closer to the center mass of West Antarctica, the Pine Island Glacier serves as one of the most important of these flood gates. In total, the large grounded glaciers in what could best be termed as an ice bottle neck hold back about 10 percent of all of West Antarctica’s interior ice mass. But just last year a huge rift that formed in this glacial buttress during 2013 cracked wide open — causing three massive icebergs totalling ten times the size of Manhattan to break off.

According to a new study, warm ocean water flooded far inland along the underside of the Pine Island Glacier. It ate away at its base and then spilled down-slope to cut out a melting hollow in the glacier’s heart. Ultimately, an enormous crack formed within the glacier 20 miles away from where the ice mass meets the ocean at the surface.

(Massive crack forms in the Pine Island Glacier, then causes three very large icebergs to break off during 2015. A new study finds that the Pine Island Glacier is melting from the inside out and an inland flood of warm ocean water is causing both the melt and the formation of large rifts in the ice. Scientists believe that these could be the first signs of a significant collapse of West Antarctica that could occur without our lifetimes. Video source: Ohio State.)

Then, in 2015, gigantic chunks of ice covering 225 square miles broke off from the Glacier and floated out into the Amundsen Sea. This was the second series of icebergs to break off from the Pine Island Glacier in as many years. And scientists were notably very concerned.

Pine Island Glacier is particularly vulnerable because it sits on a reverse slope. In other words, a below sea level bed slopes lower as you progress toward the center of the Continent. And, in fact, large portions of West Antarctica are below sea level (see topographic image below).

Pine Island Glacier itself rests upon an opening to one of the deepest valleys sloping inland. At the location of the Pine Island glacier a rift between 500 and 2,000 feet below sea level runs down toward a central region of West Antarctica that sits between 2,000 and 6,000 feet below sea level. And within this basin is a pile of glacial ice that from bedrock to its highest point above sea level towers two and a half miles high. The very valid concern for this glacier is that melt and rifting, once started, will tend to accelerate — taking out larger and larger chunks of the inland ice as it is exposed to the warming ocean and heating atmosphere.

The Larger Picture — Glacial Flood Gates are Cracking Open

Larsen C and Pine Island Glacier serve as but two of the many flood gates that run all along the coast of West Antarctica and East Antarctica. But the increasing flows of warm water coming in from the ocean and a related rise in the frequency of events where large masses of ice break off from buttressing glaciers and ice shelves has put West Antarctica in danger of facing a near term collapse.

west-antarctica-below-sea-level

(Islands encased in ice. Much West Antarctica, on the left side of this topographic image, sits between 0 to 6,000 feet below sea level. If the buttressing glaciers and ice shelves like Larsen C and Pine Island are lost, there is little to prevent the warming oceans from flooding inland and setting off a rapid cascade of melt and seaward outflow. Scientists now believe that such a collapse could happen within our lifetimes. Image source: Antarctic Bedrock.)

With information from new glacial stability assessments in hand, Antarctic ice specialists are warning that the western region of this frozen land may collapse in a major melt event that over the next 100 years could raise sea levels by 10 feet. And West Antarctica is but one of three global regions — including Greenland and East Antarctica — capable of contributing significant glacial outbursts during this period.

Links:

West Antarctica Ice Shelf is Melting From the Inside Out

With a Collapsing West Antarctica, Sea Levels Could Rise Twice as High as We Thought

Combustion of Available Fossil Fuel Reserves Sufficient to Eliminate Antarctic Ice Sheet

Burning all Fossil Fuels Will Melt Entire Antarctic Ice Sheet

Rift in Antarctica’s Larsen C Ice Shelf

The Larsen Ice Shelves

NASA Captures Disturbing Images of Antarctica Ice Rift

Antarctic Bedrock

Pine Island Glacier Topography

Hat tip to Colorado Bob

Hat tip to ClimateHawk

Dr James Hansen — Human Warming Pushing Seas Toward Exponential Rise of Several Meters This Century

Continued high fossil fuel emissions this century are predicted to yield … nonlinearly growing sea level rise, reaching several meters over a timescale of 50–150 years. Statement from a new scientific study led by Dr James Hansen entitled Ice Melt, Sea Level Rise, and Superstorms.

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This week, Dr James Hansen and colleagues published one hell of a groundbreaking bit of scientific research. It’s a multi-disciplinary study incorporating the work of 19 top climate scientists, glaciologists, paleoclimatologists, and other Earth Systems researchers. Scientists from NASA, GEOMAR, JPL, and other top research agencies including recognized names like Dr Eric Rignot and Dr Makiko Sato all appear on the contributors list.

Global mean sea level change

(Rates of sea level rise since 1900 and associated with a 1.1 C jump in global temperatures have already shown a non-linear progression. Ice Melt, Sea Level Rise, and Superstorms attempts to pin down just how fast glacial melt rates will increase over the coming decades.)

The paper covers three topics related to the rapid accumulation of fossil fuel driven greenhouse gasses in the atmosphere and related rapid warming — Ice Melt, Sea Level Rise, and Superstorms. In other words, the paper looks into what will likely be the initiation of a Heinrich Event during the 21st Century so long as high levels of human greenhouse gas emissions continue.

A Heinrich Event for the 21st Century

For those not familiar with a Heinrich Event — it’s one of those disastrous climate change related incidents that you really don’t want to see emerge. One that drives rapid sea level rise, wrenching climate dislocations, and is likely also a trigger for regional and possibly hemispheric superstorms. Something that’s occurred numerous times in the geological past when the great Greenland and West Antarctic ice sheets warmed enough to disgorge armadas of ice bergs into the North Atlantic and/or Southern Ocean. The kind of thing that scientist Steve Pacala called a Climate Monster in the Closet. And Dr. James Hansen and colleagues’ new study is the first of its kind to scientifically explore the potential occurrence of just such a freak and dangerous event during the 21st Century.

Because the paper covers such a broad range of topics related to Heinrich Events, I’ve decided to write a two-blog post covering it. This post will focus on the ice melt and sea level rise issues. The superstorm-generating aspect of Heinrich Events — which Dr Hansen and colleagues found was capable of producing waves powerful enough to pluck 1,000 ton boulders from the sea floor and deposit them upon hillsides in the Bahamas 130 feet above sea level 115,000 years ago — is something we’ll cover in a second related post over the next few days.

Warm Ocean Waters Attacking Weak Glacial Underbellies

The chief driver of Heinrich Events is spiking rates of glacial melt issuing from the Greenland and West Antarctic ice sheets and related outflow of ice bergs and fresh water into the North Atlantic or the Southern Ocean. Hansen and colleagues’ paper builds on recent work by Eric Rignot and others who’ve found that the contact of warming ocean waters with the submerged sea faces of glacial cliffs and undersides of floating ice shelves is a primary driver for melt and ice berg release during periods of local and global temperature increase.

Heinrich Event Amplifying Feedbacks

(Illustration from Ice Melt, Sea Level Rise, and Superstorms shows how ocean stratification acts as an amplifying feedback to glacial melt. Cool, fresh surface waters generated by the initial ice release set up a kind of ocean heat conveyor belt that delivers more and more warm water to the submerged underbellies of the great ice sheets. In Greenland, prograde beds limit the amount of ice that can be released in sudden events. In Antarctica, retrograde beds below sea level set up a situation where the amplifying melt feedback is further enhanced.)

Grounding glaciers and ice shelves are, at first, weakened by slow but ramping melt rates. Eventually, the glaciers and shelves collapse due to the weakening process of melt which leads to a surge of previously buttressed ice sliding out into the oceans. As more fresh melt water expands over the ocean surface, it traps heat into deeper layers of the water column near the submerged glacial faces. So initial melt produces an amplifying feedback that delivers more ocean heat to the ice and, in turn, results in more ice rushing out into the North Atlantic or the Southern Ocean.

Exponential Rates of Glacial Melt and Sea Level Rise

It is this mechanism that Hansen and colleagues fear will come into play over the course of the 21st Century. Their paper identifies a risk that such a mechanism could set up 5, 10, or 20 year melt doubling times for Greenland, West Antarctica or both this Century. A new perspective from some of the world’s top scientists that assumes the risk of non linear melt is high enough to present a major concern. As an example, under a 10 year doubling time, the current approximate 3 mm per year sea level rise would double to 6 mm per year by 2026, 12 mm per year by 2036, 2.4 cm per year by 2046, and nearly 5 cm per year by 2056.

Doubling times in non linear events often don’t fit a pure exponential curve — instead tending to follow a series of spikes and recessions with major transitional events coming at the end of any ‘curve.’ But Hansen’s particular perspective is useful given the fact that current rates of sea level rise do not appear to be following a linear pattern and due to the fact that the mechanism for large, Heinrich Event type glacial melt spikes is becoming more supported in the observational science.

Rate of Greenland Antarctica Mass Change

(It’s still early days for Greenland and Antarctic melt. However, current trend lines do point toward a potential for multi-meter sea level rise this Century. Image source: Ice Melt, Sea Level Rise, and Superstorms.)

Early measures of Greenland and Antarctica ice mass loss imply 8-19 year melt doubling times for Greenland and 5-10 year melt doubling times for Antarctica. For reference, if both these ice systems continued to double mass loss on a roughly 10 year basis, total sea level rise by the 2090s would equal 5 meters or 16.4 feet. By contrast, a 5 year doubling time would result in 5 meters of sea level rise by the late 2050s and a 20 year doubling time would result in nearly a meter of sea level rise by the end of this Century and 5 meters worth of sea level rise by 2160.

Hansen notes that these are still early days and it is unlikely that ice sheet response trends have become clear at this stage. However, initial trend lines, though likely to be less accurate, appear to pose some cause for concern. In addition, Hansen points out that rates of sea level rise are less likely to be constrained by ice sheet inertia during periods when global temperatures are rapidly rising. Projected rates of global temperature increase in the range of 1-5 C this Century is on the order 20-100 times faster than during the end of the last ice age — at the upper end covering all of the 10,000 years worth of ice age warming in just one Century. And Hansen notes that this potentially extreme rate of temperature increase poses a much greater risk of rapid glacial destabilization than is indicated by current IPCC glacial melt models.

Hansen’s research also points to the likelihood that rapid glacial melt would temporarily put a break on rates of global atmospheric warming by cooling local ocean surfaces and increasing the rate of heat transfer into middle ocean layers. And it’s this energy flip-flop and related heightened imbalance that provides a pretty severe potential storm set-up as rates of glacial melt ramp up.

Links:

Ice Melt, Sea Level Rise, and Superstorms

Climate Guru James Hansen Warns of Much Worse Than Expected Sea Level Rise

Dr James Hansen

Dr Eric Rignot

Dr Makiko Sato

Heinrich Event

Climate Monsters We Want to Keep in the Closet

Melting in West Antarctica Could Raise Seas By 3 Meters

Hat Tip to DT Lange

Hat Tip to Colorado Bob

Hat Tip to TodaysGuestIs

For Miami, Sea Level Rise Has Already Gone Exponential

(AP story showing the effects of 9 inches of sea level rise over the last 100 years. What the story doesn’t mention is that half of this sea level rise has occurred within the past 16 years and fully a third of it has occurred within the past 5 years. Video source: Associated Press.)

This week, Miami is scrambling to deal with a flooding emergency.

But the cause is not the looming approach of a major hurricane or even a powerful tropical storm. The flood emergency for the coming three days is simply a seasonal astronomical high tide. Something they are now calling a King Tide. A condition that arises due to solar and lunar alignment a few times every year. A gravitational flux that pushes high tides another foot or so above the normal range.

Decades or even years ago, astronomical high tide wasn’t so much of a problem for Miami. Now, it means flooded roads and runways. It means salt water backing up through city drainage and municipal water systems. It means sea walls over-topped. It means lawns, properties and businesses covered in water.

The crisis is so serious that the city has already allocated more than 400 million dollars to deal with the problem. And this week, crews and flood prevention planners are scrambling to face the rising seas.

Rapidly Rising Waters

 

Miami Sea Level Trend

(Peak high tide trend from 1998 through 2014 shows sea levels rose by 4.3 inches over the past 16 years with most of the rise occurring since 2008. Image source: Dr. Zhaohua Wu, FSU)

At issue is the fact that Miami is facing a climate change driven sea level rise that is in the process of going exponential. A ramping rate of water rise that is being driven by a combination of glacial melt, ocean expansion due to warming, a backing up of the Gulf Stream which is raising waters all along the Eastern Seaboard, and a continuation of land subsistence in South Florida due to a variety of factors.

From 1914 through 1998, sea levels rose by an average of 0.06 inches per year — a rate that was barely noticeable to residents and city planners alike. But from 1998 to 2009 the pace increased to a more troubling 0.14 inches per year. And from 2009 to the present year the pace again jumped to a terrifying 0.67 inches per year.

An exponential rate of sea level rise that, in the past year alone, raised Miami’s surrounding ocean waters by 0.86 inches. Should the observed sea level rise over recent years continue, Miami will be facing 6-9 feet of additional water by the end of this century and not the 3-4 feet currently predicted.

Vulnerable Miami, South Florida

Miami is particularly vulnerable to such rapid rates of sea level rise for a couple of reasons. First, most of Miami is less than four feet above 20th Century sea levels. So even moderate rates of sea level rise put major portions of the city under water. Second, the city sits on porous limestone. The rock, riddled with holes, leaks like a sieve. So building sea walls won’t help Miami much as water will simply rise up through the rocks themselves.

Because Miami is so low-lying and surrounded on almost all sides by water, it is often seen as one of the most vulnerable cities to human-driven climate change. However, the geological conditions are not unique to Miami and remain a problem for almost all Florida cities. The porous limestone is a feature of the entire Florida Peninsula. So the problems Miami is facing now will become problems for hundreds of cities and communities up the coast and in more central regions of the state as well.

At most immediate risk is all of South Flordia. Miami-Dade and Broward Counties have about half of their residents living below the 4 foot above sea level line. Collier and Monroe counties also boast very large populations within just 4 feet of already rapidly rising seas. Such a rise would generate inland water upwelling throughout much of south Florida and the Everglades even as many coastal regions faced inundation. Small, low-lying islands and barrier zones would be swallowed by the sea or broken by incursions through weak points. The mangroves, already in retreat, would be swiftly beaten back. Inland lakes, invaded by higher pressure salt water from below, would also rise.

FinalUnifiedSLRProjection

(Sea level rise observations and projections through 2060 for Key West. Note that observations end at 2009 and that the tidal gauges have recorded a 3 inch sea level rise from 2009 through 2014 for Miami — already hitting the bottom range of expected sea level rise by 2030. Image source: Southeast Florida Regional Climate Change Compact Page.)

As an example, seasonal high tides are already having an effect on the Delray Beach region that is starkly similar to problems now plainly visible in Miami. In the historic Marina neighborhood, water bubbles up from storm drains and spills over the banks of the Intracoastal Waterway into streets.

Charle Dortch, a resident for 17 years said in a recent interview with the Sun Sentinel:

“It’s progressively getting worse. The water is coming up the roadway right into people’s front yards. It’s flooding the parking area. It’s coming up higher and higher every year.”

Links:

Water, Water Everywhere: Sea Level Rise in Miami

Southeast Florida Regional Climate Change Compact Page

Southwest Florida Governments Not Planning For Sea Level Rise

The Ocean is Already Higher

In Miami, The King Tide is Coming

Associated Press

Sea Level Rise: Everglades

Florida and Rising Seas

Dr. Zhaohua Wu, FSU

(Hat Tip to TodaysGuestIs)

Ten Cubic Kilometers of Ice Lost From Jakobshavn Glacier in Less than One Month

How large is a cubic kilometer? Think of something the size of a mountain. Now multiply that by ten and you end up with a veritable mountain range. Think of it. An entire mountain range of ice. That’s a good rough comparison to the volume of ice lost from just a single Greenland glacier over the course of a mere 26 days from May 7 to June 1 of 2014.

Jakobshavn Ibrae Ice loss 2014

(Massive ice loss from Jakobsbavn glacier captured by Espen Olsen. Image source: The Arctic Ice Blog.)

For according to reports from expert sea ice observer Espen over at the scientist and ice researcher camp that is Neven’s Arctic Ice Blog, about 7.5 square kilometers over an ice face about 1,300 meters tall (when including the above and below sea level ice front) shoved off from the great Jakobshavn Ibrae glacier during the past month. It was a period of time well before peak Greenland warming and one that featured a collapse of ice into the heating ocean even larger than the epic event caught on film during the seminal documentary Chasing Ice.

The Fastest Glacier in Greenland

Flowing at a speed of 46 meters per day, Jakobshavn is currently Greenland’s fastest glacier. Containing enough ice to raise global sea levels by 1.5 feet all by itself, the glacier is one of many of the Earth’s ice giants currently in the throes of irreversible decline.

Human-warmed subtropical Atlantic waters are funneled by ocean currents to the great glacier’s base. There, the high heat capacity does serious harm to the its weak underbelly, resulting in what is now an unprecedented seaward surge.

Since the 1990s, Jakobshavn’s forward rate of motion has tripled. But according to recent scientific reports, the glacier may just be at the start of an exponential spike in velocity. For as the glacier retreats it falls into a deepening chasm that exposes its front to greater and greater volumes of the warming ocean’s waters. The warm waters deliver more heat over the glacial face as it deepens even as a multiplication of melt lakes on the surface of the inland ice provide added lubrication and buoyancy to the ice base flowing into the chasm.

Greenland Bedrock Map

(Greenland map showing location of the Jakobshavn Glacier with close view of a deep channel in the bedrock. This channel was likely carved by previous discharge and at its deepest point is now more than 1,000 meters below sea level. Image source: NASA’s Earth Observatory.)

Estimates of energy transfer from the warming ocean show that Jakobshavn could reach a speed ten times 1990s values over the coming years. Ominously, the past two month’s immense calving event has shoved a large section of glacier closer to what could best be described as a high velocity melt chamber.

Greenland — An Archipelago Covered in Ice

Unfortunately, Jakobshavn is just one of Greenland’s many giant glaciers fronting deep and long chasms stretching far into the ice interior. Recent research from NASA’s Ice Bridge project revealed numerous deep rifts plunging for scores of miles into the ice sheet. The overall picture portrayed by the new study was that of an archipelago island system locked in the grip of two mile high ice mountains and riddled with deep bedrock canyons that join in a low-lying interior basin. A geography in which there is almost nowhere for ice to hide from the severe melting stress of Earth’s human-warmed oceans.

Due to this uniquely vulnerable topography lead Ice Bridge researcher Mathieu Morlighem, a UC Irvine associate project scientist concluded that:

“The glaciers of Greenland are likely to retreat faster and farther inland than anticipated – and for much longer – according to this very different topography we’ve discovered beneath the ice. This has major implications, because the glacier melt will contribute much more to rising seas around the globe.”

Human Warming Holds Numerous Large Glacial Collapses in Store

Under the current regime of human-caused climate change, the past month’s massive glacial release is likely only to be one of many. A single event of immense scale that defies imagining. Just one in an ongoing series of violent outbursts we’ve already set lose on our world.

An event of smaller, though still enormous, size was captured on film here:

(Largest glacial calving event captured on film as excerpted from the ground-breaking documentary ‘Chasing Ice.’)

It is a film that gives us some small measure of understanding of what we’ve done and what we continue to to do. For Greenland’s entire ice edge, a region unlocking ice twenty times the volume of Jakobshavn, is now in the process of deformation and collapse all while the massive glaciers of West Antarctica are also falling into irreversible release.

Links:

(Hat-tip to Colorado Bob)

The Arctic Ice Blog

Chasing Ice

NASA’s Earth Observatory

Greenland Will Be Far Greater Contributor to Sea Level Rise Than Expected

Greenland’s Jakobshavn Glacier Revs-up With Climate Change

Nature: Human Warming Now Pushing Entire Greenland Ice Sheet into the Ocean

Grim News From NASA: West Antartica’s Entire Flank Collapsing into Southern Ocean

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