Catastrophic failure of ice age dam changed ocean circulation and climate

February 12, 2016, University of Bristol
Catastrophic failure of ice age dam changed ocean circulation and climate
This study is important because of current concerns about the volumes of fresh water entering the oceans from the melting ice sheets in Greenland and Antarctica

The catastrophic release of fresh water from a vast South American lake at the end of the last Ice Age was significant enough to change circulation in the Pacific Ocean, according to new research co-authored by a PhD student from the University of Bristol.

"This study is important because we are currently concerned about the volumes of entering the oceans from the melting ice sheets in Greenland and Antarctica and this gives us an indication of the likely effects," the study's lead author, Professor Neil Glasser from Aberystwyth University said.

The study, published today in Scientific Reports, reveals that the lake, which was about one third the size of Wales, drained several times between 13,000 and 8,000 years ago, with devastating consequences.

At its high point the lake extended over 7,400km2, held 1500km3 of water and occupied a basin which now contains Lago General Carrera in Chile and Lago Buenos Aires in Argentina.

Held back by a dam formed by a large ice sheet, the lake drained rapidly as the ice sheet shrank in size.

Professor Glasser said: "This was a massive lake.  When it drained, it released around 1150km3 of fresh water from the melting glaciers into the Atlantic and Pacific oceans – equivalent to around 600 million Olympic-sized swimming pools.  This had a considerable impact on the Pacific Ocean circulation and regional climate at the time.

"Much of the freshwater drained into the sea near Golfo Peñas, south of the Chilean capital Santiago.  The fresh water would have sat on top of the salt water as it spread out so it affected the regional ocean currents.  The event affected the whole of southern South America and would have led to lower rainfall in winter and cooler ocean and air temperatures around Cape Horn, with the effects felt as far east as the Falkland Islands."

The study, which applied different techniques to investigate the size of the former lake and how it drained, was undertaken by an international team of scientists, including Max Holloway, a PhD student in Bristol's School of Geographical Sciences.

Samples of sediments deposited by the former lake were collected to determine the age of the lake drainage events using a laboratory technique known as single-grain optically stimulated luminescence dating.

Digital Elevation Models (DEMs) were applied to identify former lake shorelines and their altitudes and drainage routes and to calculate the volume of water released as the drained.  An ocean-atmosphere climate model was used to determine the impact of dumping this amount of freshwater into the Pacific Ocean.

Explore further: Greenland's ice sheet plumbing system revealed

More information: Neil F. Glasser et al. Glacial lake drainage in Patagonia (13-8 kyr) and response of the adjacent Pacific Ocean, Scientific Reports (2016). DOI: 10.1038/srep21064

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SamB
1.4 / 5 (11) Feb 12, 2016
Wow.. An we ended up with an amazing planet. So, if we repeat, we will end up with an even more amazing planet.
AGreatWhopper
4.1 / 5 (13) Feb 12, 2016
Not as long as vermin like you are trolling science sites.
antigoresockpuppet
2.8 / 5 (13) Feb 12, 2016
Science site? This site is troll owned and pimp operated. If you're neither, you're little people and have no rights.

An ocean-atmosphere climate model was used


Sugar Daddy says those are always wrong. His armchair modeling has far more variables, addresses far older data, and has much better maths. That's the thing the mainstream types don't understand. You know what earns you the label "troll"? Being able to do the maths in your head- at least the bottom line- without mechanical aid. "Mainstream scientists" can't to diddly without them. That's why they're jealous.

Think about it. Why the constant back and forth? If they're correct about everyone recongizing a crank, then why bother to point it out? They argue because they're jealous. The opposive of love is not hate, it's indifference. How many "good scientists" at this site are indifferent? That speaks to passion. If we were as vacuous as they claim, we wouldn't inspire passion.
jim_xanara
1.7 / 5 (11) Feb 12, 2016
ROFLMAO Put that in your pipe and smoke it Captain Stumpy. 3 1/2 cents and all the other deluded "correctors".
antigoresockpuppet
2.6 / 5 (5) Feb 12, 2016
That breeze "the correctors" are feeling from behind would be the presence of a new anal oriface.
Caliban
4.3 / 5 (6) Feb 13, 2016
ROFLMAO Put that in your pipe and smoke it Captain Stumpy. 3 1/2 cents and all the other deluded "correctors".


What, exactly, are you on about in this post, jix?

I've read plenty of comments here that include zero context, but this is the first time that the context was not even detectable as a result of its absence that I have ever encountered.

Besides its being an obvious jibe at Captain Stumpy, I mean.

And since that part --and that part only-- was obvious, then what did you mean by it? How and why and in what way can the content of this article be used to shed a negative light upon Captain Stumpy?

Oh, that's right --I forgot I was addressing a genuine, Carbuncle-Crested, Spotty-Bottomed Lesser Troll.

My mistake.
Captain Stumpy
3.7 / 5 (6) Feb 13, 2016
Oh, that's right --I forgot I was addressing a genuine, Carbuncle-Crested, Spotty-Bottomed Lesser Troll.

My mistake.
i thought she was a brown-nosed cretinous bottom feeding loon... but i can see how they can be mistaken for each other...

and BTW, i have no freakin idea what the troll is on about either

but then again, i still can't figure out what xanax is on about most of the time... this is probably because we can't see the same delusion as she does?

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