Thread: Dramatic sea level rises from the past

Controversial study that suggest sea level has risen very quickly during the last interglacial.
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Coral Fossils Suggest That Sea Level Can Rise Rapidly

Evidence from fossil coral reefs in Mexico underlines the potential for a sudden jump in sea levels because of global warming, scientists report in a new study.
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Andrew C. Revkin blogs about climate and sustainability. Join the discussion.
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Among Climate Scientists, a Dispute Over ‘Tipping Points’ (March 29, 2009)

The study, being published Thursday in the journal Nature, suggests that a sudden rise of 6.5 feet to 10 feet occurred within a span of 50 to 100 years about 121,000 years ago, at the end of the last warm interval between ice ages.

“The potential for sustained rapid ice loss and catastrophic sea-level rise in the near future is confirmed by our discovery of sea-level instability” in that period, the authors write....

http://www.nytimes.com/2009/04/16/sc...=1&ref=science
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Like all science this is going to take some confirmation and reconciliation with other studies which suggest there are some physical limits to how fast ice can melt and effect sea level.

Lynx

The one thing we know for sure is that sea levels are not stable. There is a coral reef off the Great Barrier Reef, carrying dead corals of a type that thrive only in surface waters - in bright sunlight. Yet this reef is 45 metres below sea level!

Currently sea levels are rising at about 3 mm per year. This is not, in itself, enormously worrying, since it means only 300 mm in 100 years (one foot). Even countries like the Maldives could cope with that. There are a lot of people who suggest that sea levels will rise faster in future, but that is definitely not cast in concrete. James Hansen - the professor who first publicised global climate change around 1980 - has claimed that sea levels will rise something like 6 metres by the year 2100. I doubt that is likely. The IPCC predicts less than half a metre for the same time period.
http://www.geology.iastate.edu/gccou...estimony06.pdf

There are lost cities that have been found under the sea (one off Alexandra), showing that sea levels have risen substantially in historic times. Archaeologists in Britain are carrying out underwater research into stone age cultures, since they lived on land in areas now flooded by rising sea levels.

"Evidence from fossil coral reefs in Mexico underlines the potential for a sudden jump in sea levels because of global warming, scientists report in a new study."

global warming is one of the cause of this! Sad to say, a lot of people today don't know how to take good care of our environment. We're worthy to suffer!


Science News and Reasearch

I've been wondering about melt rate of ice-age sea-level glaciers. If the glacier is sitting on (then) sea level (?continental shelf?) would not salt water lapping the bottom accelerate melting? Wouldn't that set off a worldwide fast thaw as melt water raised sea level, exposing more and more coastal glaciers to salt water?

Originally Posted by Lynx_Fox

Controversial study that suggest sea level has risen very quickly during the last interglacial.
--
Coral Fossils Suggest That Sea Level Can Rise Rapidly

Evidence from fossil coral reefs in Mexico underlines the potential for a sudden jump in sea levels because of global warming, scientists report in a new study.
Skip to next paragraph
Dot Earth

Andrew C. Revkin blogs about climate and sustainability. Join the discussion.
Related
Among Climate Scientists, a Dispute Over ‘Tipping Points’ (March 29, 2009)

The study, being published Thursday in the journal Nature, suggests that a sudden rise of 6.5 feet to 10 feet occurred within a span of 50 to 100 years about 121,000 years ago, at the end of the last warm interval between ice ages.

“The potential for sustained rapid ice loss and catastrophic sea-level rise in the near future is confirmed by our discovery of sea-level instability” in that period, the authors write....

http://www.nytimes.com/2009/04/16/sc...=1&ref=science
--

Like all science this is going to take some confirmation and reconciliation with other studies which suggest there are some physical limits to how fast ice can melt and effect sea level.

Lynx

Isn't this the same crew that forcasted that sealevels would rise 200 feet by the year 2000? The warming that occured 121,000 years ago was no more extreme than what has happened since the little ice age of the 17th century, yet the sealevels only rose so gradually that hardly anyone noticed.

Even if it were true, our primitive anscestors had no problems adapting. No need for cap and trade.

Even if it were true, our primitive anscestors had no problems adapting.

Um, what was the population of New York City 121,000 years ago? Or of Bangladesh?

Originally Posted by Bunbury

Even if it were true, our primitive anscestors had no problems adapting.

Um, what was the population of New York City 121,000 years ago? Or of Bangladesh?

The population then was greater than it is now. Of course I am assuming that there is something to AGW. Making that assumption, both cities should be underwater by now.

Originally Posted by williampinn

Originally Posted by Bunbury

Even if it were true, our primitive anscestors had no problems adapting.

Um, what was the population of New York City 121,000 years ago? Or of Bangladesh?

The population then was greater than it is now.

Surely you can't be serious.

Well, that would explain the large number of skeletons we find from that period...

Wait, no, actually we don't...

Originally Posted by Bunbury

Originally Posted by williampinn

Originally Posted by Bunbury

Even if it were true, our primitive anscestors had no problems adapting.

Um, what was the population of New York City 121,000 years ago? Or of Bangladesh?

The population then was greater than it is now.

Surely you can't be serious.

Then again, if AGW predictions were just a hoax, then those cities should still be above water. And sealevels will continue to rise and fall gradually.

Originally Posted by Lynx_Fox

Like all science this is going to take some confirmation and reconciliation with other studies which suggest there are some physical limits to how fast ice can melt and effect sea level.

Lynx

For sure! According to my calculations, if the the entire north pole melted, sea levels would rise only approximately .5 mm. Additionally it was predicted that Antarctica would lose ice and sea levels would rise substantially in our age. It did not happen, since Antarctica is so cold, the ice isn't anywhere close to the melting point, notwithstanding any rapid warming.

Originally Posted by williampinn

Originally Posted by Lynx_Fox

Like all science this is going to take some confirmation and reconciliation with other studies which suggest there are some physical limits to how fast ice can melt and effect sea level.

Lynx

For sure! According to my calculations, if the the entire north pole melted, sea levels would rise only approximately .5 mm.

Not sure what you mean by the "entire North pole." Of course melting the Arctic Ocean will result in no increase, because it's floating. If, however, you include Greenland and some of the glaciers on Ellesmere Is. you get about 2 feet of average ocean rise.

Additionally it was predicted that Antarctica would lose ice and sea levels would rise substantially in our age. It did not happen, since Antarctica is so cold, the ice isn't anywhere close to the melting point, notwithstanding any rapid warming.

To my knowledge there's been no scientific agency that predicted that Antarctica should already have melted. Ice is melting nearly everywhere though and is contributing to the rising sea levels we've experienced over the past hundred years and continuing to rise.

Most of the physical limitations though to exist for that melting have to do with the rate glaciers can melt, rate they can move over the bedrock towards the coast, rate they'll receive more snowfall from closer available open ocean at their margins, rates of isostatic compensation etc.

Originally Posted by williampinn

Originally Posted by Bunbury

Originally Posted by williampinn

Originally Posted by Bunbury

Even if it were true, our primitive anscestors had no problems adapting.

Um, what was the population of New York City 121,000 years ago? Or of Bangladesh?

The population then was greater than it is now.

Surely you can't be serious.

Then again, if AGW predictions were just a hoax, then those cities should still be above water. And sealevels will continue to rise and fall gradually.

And if pigs had wings we'd all need big umbrellas. (Bangladesh is not a city, btw, it's a country.)

Originally Posted by williampinn

Originally Posted by Bunbury

Even if it were true, our primitive anscestors had no problems adapting.

Um, what was the population of New York City 121,000 years ago? Or of Bangladesh?

The population then was greater than it is now. Of course I am assuming that there is something to AGW. Making that assumption, both cities should be underwater by now.

come again ? the human population of New York City was zilch 121,000 years ago