A new study published in Science this week (Dorale et al 2010) indicates sea level can rise extremely quickly, as fast as “Twenty meters per thousand years [which] equates to one meter of sea level change in a 50-year period,” according to lead author Jeffrey Dorale, an assistant professor of geoscience at the University of Iowa. “Today, over one-third of the world’s population lives within 60 miles of the coastline. Many of these areas are low-lying and would be significantly altered—devastated—by a meter of sea level rise. Our findings demonstrate that changes of this magnitude can happen naturally on the timescale of a human lifetime. Sea level change is a very big deal.”

Phil Berardelli
ScienceNOW Daily News
11 February 2010

Something very unusual happened about 80,000 years ago, as Earth’s last ice age was getting started. Sea levels that had been dropping for thousands of years–as more and more water became trapped in expanding glaciers–suddenly rose, according to a new study. Then after a few thousand years, the levels fell again. Although the researchers haven’t found the cause of this phenomenon, they say the findings could force at least a partial rethinking of the mechanisms governing Earth’s climate.

—–

In coastal caves on the Spanish island of Mallorca in the Mediterranean Sea, the team studied stalactites encrusted with calcite. They measured the elevation of those encrustations, which were deposited like bathtub rings that mark high- and low-water levels, and then dated those deposits using the radioactive decay of traces of uranium into thorium isotopes. Based on those calculations, the researchers found that sea level 80,000 years ago had rebounded to the point where it rose 1 meter higher than it is today. And it could have risen quite quickly, as much as 2 meters per century, says geochemist and lead author Jeffrey Dorale of the University of Iowa, Iowa City.

link to the full story in Science Now here

Dorale, J. A., B. P. Onac, J. J. Fornos, J. Gines, A. Gines, P. Tuccimei, and D. W. Peate. Sea-Level Highstand 81,000 Years Ago in Mallorca. Science 327:860-863.

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Fig. 1 Encrusted speleothems at various levels in caves from Mallorca. (A) Geologic map of Mallorca (10) and location of sampled caves (red dots). (B) Schematic cross-section through a coastal cave in Mallorca showing multiple carbonate encrustation levels. (C and D) Present-day and paleo levels of encrusted speleothems related to higher (E) and lower (F) sea-level stands. (G) Typical morphology for tidal range–related carbonate encrustation (size of speleothem, 20 cm). (H) Bathymetric map of the western Mediterranean region and the predicted present-day rate of sea-level change due to GIA [adapted from (15)

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7 Responses to New study indicates sea level can rise 1 m in 50 years

  1. MarcH says:

    An interesting study with some big unknowns and conflicting results…

    From the paper…

    “our ~ +1 mMIS 5a highstand conflicts with reconstructions from raised coral reefs from uplifting coastlines (such as Haiti, Barbados, and New Guinea), which suggest that MIS 5a eustatic sea level was anywhere from 7 m (one “Greenland equivalent”) to 30 m (four “Greenland equivalents”) below present sea level (2, 3, 11, 12). Lower-than-present sea levels at
    ~80 ka have also been inferred from submerged speleothems from Grand Bahama Island (13) and coral reefs on the Florida Keys (14).”

    “We therefore consider the simple interpretation of our data that eustatic sea level during MIS 5a stood around +1 m relative to present sea level, implying less ice on Earth 81,000 years ago than today. Although this interpretation conflicts with the generally accepted eustatic sea-level curve based on the far-field sites of Barbados and New Guinea, it is consistent with a number of other estimates from around the world, including those from the Bahamas, the U.S. Atlantic Coastal Plain, Bermuda, Cayman Islands, and California (4, 6, 22–26) (Fig. 2B).

    Local uplift or subsidence at these rates is common.

  2. J.Roff says:

    MarcH: You are selectively quoting parts of the paper to try and muddy the issue. I’ll quote this statement from the paper instead:

    These rates of sea-level change nominally approach 20 m per thousand years (ky), which is comparable to the meltwater pulses of the last major deglaciation (21) and almost 30 times larger than the largest observed or predicted rates of GIA (15).

    Local uplift or subsidence is not common at this rate.

  3. MarcH says:

    J Roff, The issue is a very muddy one. The rate is not spectacular. Check this reference for instance:

    Glacio-Isostasy: New Data from West Greenland and Geophysical Implications

    http://gsabulletin.gsapubs.org/content/85/2/219.abstract

    “The initial uplift rate of about 105 m per 1,000 yr is the highest reported for Greenland. The other curve represents a zone ∼50 km west of the present ice sheet, where 75 ± 5 m of postglacial uplift began ∼7,300 yr B.P. at an initial rate of about 60 m per 1,000 yr.”

    105 m per 1,000 yr now that’s moving.

  4. Joseph says:

    I’ve been looking at a SL reconstruction that covers this period by Arz et al. From 82800 BP to to 78400 BP, SLR is about 42 meters. That’s about a meter per century – or half of what the article says. There’s a period of no rise, spanning over 1,000 years, however. So it could be a bit more than 1 meter/century.

    My two most recent posts are on this topic.

  5. Phil M says:

    Im waiting for the rebuttal of this article or something like it to appear on either Bolt or Akermans blog.

    Bolt: “New study by (Dorale et al 2010) grossly exagerates sea level rise stating that we could have 1M sea level rise in 50 years by next week! Exxon reports its more like -1M . I also have this paper from (Schmuck et al 2010) from whats up with that blog stating that even if we DID have that much sea level rise, then it could only be beneficial & we need to adapt. Sea level rises will only be MORE beneficial, as fish will have more water to live & breed in & boats & ships can sail over dangerous reefs with ease & it will absorb even MORE Co2″

    Bolt fan: “this is an outrage Andrew! Thankyou for your excellent journalistic skills in exposing this & telling us the truth!”

    Akerman: “I spoke to Dorale by phone tonight & he/she assures me that his/her main aim was to de-industrialise the west, get more grants, destroy capitalism & will say anythng to achieve this..Oh & he/she assures me also, that they like to wear a gimp suit”.

    Akerman fan: “I knew it!! more proof of the conspiracy! The game is over warmists!!!!!!!”

  6. John Bruno says:

    wonderful comment Phil M! So close to the truth I doubt a skeptic wouldn’t recognize it as sarcasm. Just all the conservative that don’t realize the Colbert report is mocking them. And the denial bloggers that latched onto this farse post we did, not realizing it was a sarcastic joke: http://www.climateshifts.org/?p=1000

  7. Phil M says:

    Ahaha John, nice story in that link, I hadnt seen it.I’ve just recently found this great blog.

    “this sighting is proof”…..Gold
    “overturns that IPCC “report” and the thousands of “scientific studies”……Gold
    “this news comes on top of the fact that it got really freaking cold in my town a few weeks ago.”…..Platinum

    Like Lee Bowman from Bondi. I believe his phones are running hot from all of the scientists around the world ringing him in relief & elation that they no longer have to slave over satelite data or check gauges to measure sea level rise, they can just ring Lee Bowman for the latest measurements.

    http://www.theaustralian.com.au/news/penny-wong-signals-doom-for-iconic-beaches/story-e6frg6n6-1225831970915

    Scientists schmientists, they dont even LIVE there!!! How could they possibly know if there was any change? Lee says there is “no change” & I take the man on the grounds word over the guy with the bunsen burner & maniacal grin on his face any day.

    Its just forehead slapping stuff to see some of the stories that appear in the blogosphere & the stuff that comes out of newscorp is just mind blowing ignorance. Yet they never question it. In fact they hold science by opinion, blog & petition in very high regard it seems.

    The dunning-kruger effect, mixed with a bit of confirmation bias, throw in a dash of political ideology & presto, climate change skeptic.

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