[dohboi]

Thawing Permafrost: The speed of coastal erosion in Eastern Siberia has nearly doubled

The high cliffs of Eastern Siberia – which mainly consist of permafrost – continue to erode at an ever quickening pace. This is the conclusion which scientists of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research have reached after their evaluation of data and aerial photographs of the coastal regions for the last 40 years.

According to the researchers, the reasons for this increasing erosion are rising summer temperatures in the Russian permafrost regions as well the retreat of the Arctic sea ice. This coastal protection recedes more and more on an annual basis. As a result, waves undermine the shores. At the same time, the land surface begins to sink. The small island of Muostakh east of the Lena Delta is especially affected by these changes. Experts fear that it might even disappear altogether should the loss of land continue.

This represents another feedback. Along the very long coasts, permafrost doesn't have to melt slowly from the top down. It's calving into the sea, similar to what glaciers do. Since these are very shallow coastal waters, nearly all the carbon in that permafrost would go straight into the atmosphere. And the longer the seas stay ice free near the coast every year, and the more of the sea is open, the more erosion there will be just from the mechanical action of the larger waves, let alone the melting effect of ever-warmer waters and air.

If the average temperature rises by 1 degree Celsius in the summer, erosion accelerates by 1.2 metres annually...

During the past two decades, there were, on average, fewer than 80 ice-free days in this region per year. During the past three years, however, we counted 96 ice-free days on average. Thus, the waves can nibble at the permafrost coasts for approximately two more weeks each year...

During the past 40 years, the coastal areas surveyed retreated on average 2.2 meters per year.

“During the past four years, this value has increased at least 1.6 times, in certain instances up to 2.4 times to reach 5.3 meters per year“...

OK, start with 5 meters per year and start doubling it every four years for the next 40 years and what do you get, you math geniuses out there?

And what does the rate get to after the next 40 years?

What is the total number of square meters would of permafrost land surface that will have dropped into the sea by then (and thence into the atmosphere)?

How much carbon will that represent?

Will the rate of acceleration increase or decrease as the sea gets ever warmer and wilder?

I can't imagine that the rate will stop increasing at least until there is no sea ice close to that part of the coast year round.

Is there anything that is likely to stop or even slow (or even slow the rate of increase of) this process?

ETA: As the first commenter on the site linked pointed out, similar rates of coastal erosion are being reported in Alaska. It must be assumed that such rates are typical around much of the Arctic Ocean. So put that into your equations and smoke it.

[Plantagenet]

Its not just the permafrost in the sea cliffs. There are extensive areas of the shallow continental shelf that contain permafrost that was formed during the last ice age when sea level was -130m below current levels. The subsea permafrost is also thawing and releasing methane and CO2.



We've got some bad juju going on up here in the Arctic.

[dohboi]

Good point, plant. And there is a lot of erosion going on further inland where there are slopes, rivers and streams.

Note that the article points out that there are islands that are well on the way to disappearing completely, from this increase in coastal erosion.

By the way, plant, I just saw this about fires in Alaska:

http://www.climatecentral.org/news/alas ... fire-16678

The Mississippi wildfire, which started in May about 70 miles southeast of Fairbanks, flared up again on Oct. 28, when strong winds were blowing and there were record warm temperatures in the lower 60s.

That's crazy! It started in May, and is still burning at the end of October/beginning of November???

Are you getting smoke from that thing where you are?

[Tanada]

The thing I wonder is, how far inland will these permafrost benches erode before the ocean meets solid land like bedrock which will form the shoreline? Along the coasts of the Great Lakes and I presume the oceans and seas there is a layer or wet soil on top of bedrock off shore, and onshore the beaches are where loose material is piled up slope on the bedrock above the water line. Clearly these permafrost bench formations are piled up high above the bedrock so the sea can erode away the foundations and cause them to collapse. Looking at my old atlas it says much of Siberia is lowland swamp, which means the water table is close to the surface of the soil and bedrock could be very deep. If that is the case then much of Siberia will end up flooded if sea levels rise very much.

[Keith_McClary]

Looking at my old atlas it says much of Siberia is lowland swamp, which means the water table is close to the surface of the soil and bedrock could be very deep.

Is there a water table in permafrost? (It can be hundreds of metres thick.)

[Tanada]

Looking at my old atlas it says much of Siberia is lowland swamp, which means the water table is close to the surface of the soil and bedrock could be very deep.

Is there a water table in permafrost? (It can be hundreds of metres thick.)

As I understand it the Water Table is how far down you have to dig before you find flowing water. I don't think you do find a water table in deep Permafrost because it extends right down to the bedrock and sometimes beyond in the far north, but in the area's where the permafrost is thinner their is a water table right below the bottom of the permafrost. We see evidence of this in the Clathrate deposits that the USSR and later Russia has exploited in Siberia. In those cases the Methane Clathrates were right at the bottom boundary of the Permafrost which acted as a reservoir cap for the Natural Gas seeps below. They produced gas two ways, by pumping water out depressurizing the clathrates and disassociating the gas, and by injecting warm surface waters into the water table where they melted the clathrates and dissociated the gas for production.

In the case of the bench formations on the Arctic shore I suspect the water table is currently frozen solid, but as the sea water causes the permafrost to melt at some time a mobile water table will be formed.

[dohboi]

Believe it or not, I had forgotten about sea level rise. It looks like, at least along the coast, there is quite a bit of low lying ground:

https://www.google.com/search?q=sea+lev ... 000%3B1091

I do wonder how fast the bedrock rises above current sea level. I'm betting a lot of those areas that show no higher than about 12 meters above sea level now are almost all permafrost to that depth. Keep in mind again that some areas in the Lena river basin have it to a depth of about a mile.

[rollin]

This is a double edged sword. As soil thaws and releases methane and CO2 it disappears into the sea to be replaced by water. So both increasing GHG and increasing ocean surface (very low albedo) cause warming.
The poles control about 5% of the albedo of the planet. That is about 13 watts/m2, so even if only 1% of that control is unleashed it is greater than the GHG effect. That is over 2 watts/m2 additional heating. Goodbye next ice age and goodbye to freezing winters in the temperate zone.

[dohboi]

South Florida City Votes To Secede In Last-Ditch Effort To Avoid Being Swallowed By The Sea

http://thinkprogress.org/climate/2014/1 ... evel-rise/

One small city in South Florida is willing to secede from the state if it means the threat of sea level rise will finally be taken seriously.

The city commission of South Miami, FL — a city that sits just west of the University of Miami in Coral Gables — passed a resolution this week that calls for Florida to be split into a North Florida and a South Florida, a creation of an additional state that would allow South Florida to take climate change preparation and adaptation into its own hands.

“It’s very apparent that the attitude of the northern part of the state is that they would just love to saw the state in half and just let us float off into the Caribbean,” South Miami Mayor Philip Stoddard said. “They’ve made that abundantly clear every possible opportunity and I would love to give them the opportunity to do that.”

Under the northern border of South Florida would include the counties of Brevard, Polk, Orange, Pinellas, and Hillsborough, which would mean drawing the new state line north of Orlando, Tampa and Clearwater. South Florida would encompass 24 counties and total about 23,000 square miles, an area that houses 67 percent of Florida’s current population.

The resolution — like all other secession attempts in the U.S. apart from the one in 1775 — isn’t likely to make it very far. In order for Florida to actually split into two states, the resolution would have to be approved by Florida’s state legislature and by the U.S. Congress. But the three South Miami councilmembers who voted the resolution into being still think the subject of sea level rise is serious enough to make the secession statement.

[Tanada]

Don't be too quick to dismiss this idea, Kentucky used to be part of Virginia and Tennessee used to be part of North Carolina. Not to forget Maine used to be part of Massachusetts as well.

[dinopello]

I don't see how seceding will avoid inundation? It's not like South Miami Beach will just swish down the street to a new party?

As the article states - the 24 counties included in the secession would have 67% of Florida's population and I just calculated based on available data that the seceded part currently generates 82% of Florida's revenue. They couldn't stop SLR but they could decide to spend their money on flood mitigation like the Netherlands.

[ritter]

hey couldn't stop SLR but they could decide to spend their money on flood mitigation like the Netherlands.

Won't work with porous limestone geology. Too many holes to plug even if the seawalls hold!

[basil_hayden]

The mitigation to sea level rise in South Florida IS to move to North Florida, duh.

This is what happens when all you do is coke and go to the beach.

Time to buy land in north Florida and wait for the Miamians!

[jupiters_release]

Sometime I watch Million Dollar Listing Miami.

[dohboi]

PULEEESE RE-ENSTATE QUOTE-O'-THE WEEK AND PUT THIS AS THE FIRST ONE:

The mitigation to sea level rise in South Florida IS to move to North Florida, duh.

This is what happens when all you do is coke and go to the beach.

Time to buy land in north Florida and wait for the Miamians!

[dinopello]

This is what happens when all you do is coke and go to the beach.

I'm just curious - what happens ? Sea level rises ? Decide to secede ?

[dohboi]

dino, dude, you're not supposed to, like, try to parse this with some low level logic-oriented mind set--it's more like on a koan level--you either intuitively grasp the whole thing or...well, your just not there yet.

http://www.youtube.com/watch?v=sYsw0KVRjCM

[basil_hayden]

This is what happens when all you do is coke and go to the beach.

I'm just curious - what happens ? Sea level rises ? Decide to secede ?

What happens while doing coke and going to the beach all day is that you decide to secede, then after the coke buzz wears off, you find yourself underwater thinking to yourself "damn, we shouldn't have seceded, we should have bought North Florida (maybe even South Georgia) since we have 75% of the population and 82% of the worth."

But it's too late, you blew your money on coke and had a blast on the beach, with al the other pirates.

Thanks for the opportunity to explain!

[dinopello]

This is what happens when all you do is coke and go to the beach.

I'm just curious - what happens ? Sea level rises ? Decide to secede ?

What happens while doing coke and going to the beach all day is that you decide to secede, then after the coke buzz wears off, you find yourself underwater thinking to yourself "damn, we shouldn't have seceded, we should have bought North Florida (maybe even South Georgia) since we have 75% of the population and 82% of the worth."

But it's too late, you blew your money on coke and had a blast on the beach, with al the other pirates.

Thanks for the opportunity to explain!

No problem, but I thank you! I've never done coke so I didn't know!

Between living in south Georgia and some great memories of a blast on a beach though - I'm not sure which is the right move.