Ice Age Floods cause mass extinctions?

[nannoh]

Warming trend in the Himilayas

Right off the bat the Global Warming specialists would call this an indication of just that - global warming - I will only go as far as to say that this article points to a warming in the Himalayan region.

Chinese and foreign researchers call for regional cooperation in fighting against the potential flooding from rapidly melting glaciers in the Himalayan region.

Chinese researchers are considering sharing satellite monitoring resources and air-borne remote-control surveys with neighboring nations like Nepal and India.

Ren Jiawen, a top Chinese glacial researcher with the Chinese Academy of Sciences, said that a regional approach will upgrade the monitoring and combat systems of such a transnational issue.

Such an approach has also been proposed by researchers from Nepal and the United Nations' Environment Program (UNEP).

The frequency of glacial floods has risen over the past three decades.

Tens of thousands of residents are at risk from the floods along with people's properties and businesses, having the potential to cause havoc on the region's economy.

According to the latest UNEP report, which was released in April, at least 44 glacial lakes in Bhutan and Nepal could burst banks in five years.

Surrenda Shrestha, regional co-ordinator in Asia for UNEP's Division of Early Warning and Assessment, has also warned that other areas in the Himalayas and across the world are in a similar critical state.

About 12 glacier incidents have been recorded in China's Tibet since 1935. The latest one took place in 1981 and destroyed three concrete bridges and crippled a long section of the Nepal-China Highway.

P.K. Mool, a leading researcher from the Nepal-based International Center for Integrated Mountain Development, urged joint efforts in inventory, monitoring, mitigation work and early warning systems.

UNEP said it is ready to assist by mobilizing necessary resources for regional partnerships in the Himalayan area.

On average, air temperatures in the Himalayan region are 1 degree C higher than during the 1970s, a rise of 0.06 degrees C per year, according to the UNEP report.

http://english.people.com.cn/200206/03/eng20020603_97024.shtml

 

[Andre]

Glacier waxing and waning depends on two factors, temperature and precipitation. Have we detailed records of both?

 

[nannoh]

Glacier waxing and waning depends on two factors, temperature and precipitation. Have we detailed records of both?

I'd like to know myself. The other discrepancy is that the article mentions 8 glacial floods since around the 1930s yet only sites that temperatures have risen a degree per year since 1970. Was there more rainfall in the years before 1970 that caused melting and flooding? Was there a warming trend that was continuing through the 1930s that caused the floods?

 

[nannoh]

Glacier waxing and waning depends on two factors, temperature and precipitation. Have we detailed records of both?

This portion of an abstract about the area may be of some help in determining an answer to your question.

Cryosphere-Climate Interactions (IAMAS [ICCl, ICPM], IAPSO, IAHS) 

The result shows that the central Himalayas has suffered a dry period in early 1800-1820, thereafter a wet condition between 1820-1930, and again a dry period since 1930 to present. Moreover, there exists a strong negative correlation between the precipitation in central Himalayas and the northern global temperature. According to IPCC reports, a global temperature will increase of 0.1-0.2?/10a. If this is the case, the glaciers on Himalayas, including our studying site, have been continual retreating, decreasing precipitation and accumulation and negative mass balance.

http://www.cig.ensmp.fr/~iahs/sapporo/abs/jsm10_p/007366-1.html

and about temperature, Andre will like the lack of support behind using isotopes as a measure of temperatures and other past meterological conditions.

The factors that govern the values of stable isotopic ratios
in snowfall are enigmatic and at present, no satisfactory model has been developed
to link them directly with any single meteorological or oceanographic factor. This
is particularly problematic for the high elevation tropical glaciers, where com-
plications arise not only from continental effects, but also from altitude effects
associated with convection which is the primary precipitation mechanism over
tropical South America and the monsoon dominated regions of Asia.

http://72.14.253.104/search?q=cache...ayas+1930+-+present&hl=en&gl=ca&ct=clnk&cd=22

 

[nannoh]

Extintion Models

Physical Menaces to Long Term Sustainability

The article linked below does not mention Ice Age Floods as a factor contributing to mass extinction. In fact, it points out how tough the Human species is and the kind sustainability that results from our toughness.

Every possible mechanism of extinction is reviewed here including Nuclear War, the next Ice Age, Technological terrorism and Global Warming. Humans and mammals in general appear to fare well through times like these, in the terms of species sustainability.

http://www-formal.stanford.edu/jmc/progress/menaces.html

 

[nannoh]

I see that there has been a lot of interest in this thread yet no one is posting comments. If you could find the time it would be interesting if you could post a comment explaining why you're interested in Ice Age or Glacial Flooding and add any information you have to the thread. Thank you

Here's another link that demonstrates the power of Glacial Flooding. In this case it is theorized that this kind of incident can effect the climate to a dramatic degree by halting the Gulf Stream. Andre may have an alternative story regarding this phenomenon.

Catastrophic Flooding from Ancient Lake May Have Triggered Cold Period

Paleogeography 13,400 years ago. Glacial Lake Iroquois is held back by an ice dam in northern New York. When that dam collapsed it drained into the lakes within the Champlain and Hudson Valleys, breaching the Narrows Dam (near present day New York City). It cascaded across the then exposed continental shelf to the North Atlantic Ocean. This release of meltwater reduced the flow of the Gulf Stream and caused an abrupt climate cooling in the Northern Hemisphere that lasted several hundred years.

Glacial Lake Candona drains into the North Atlantic through the St. Lawrence Valley as the ice sheet retreats from the region. The drainage of Glacial Lake Candona and the opening of the drainage out the St. Lawrence initiated another shut down of the Gulf Stream, causing the Younger Dryas cold interval.

Ocean and Climate Change Institute

Imagine a lake three times the size of the present-day Lake Ontario breaking through a dam and flooding down the Hudson River Valley past New York City and into the North Atlantic. The results would be catastrophic if it happened today, but it did happen some 13,400 years ago during the retreat of glaciers over North America and may have triggered a brief cooling known as the Intra-Allerod Cold Period.

http://www.whoi.edu/mr/pr.do?id=2078

 

[Bystander]

I see that there has been a lot of interest in this thread yet no one is posting comments. If you could find the time it would be interesting if you could post a comment explaining why you're interested in Ice Age or Glacial Flooding and add any information you have to the thread. Thank you

Here's another link that demonstrates the power of Glacial Flooding. In this case it is theorized that this kind of incident can effect the climate to a dramatic degree by halting the Gulf Stream. Andre may have an alternative story regarding this phenomenon.

http://www.whoi.edu/mr/pr.do?id=2078

Iriquois, Candona volumes compare in what magnitude to the annual flow of the "Atlantic Conveyor?" Not quite as great a disparity as throwing tennis balls at oncoming trains, but as far as affecting ocean circulation for centuries? Nerp.

 

[Andre]

Iriquois, Candona volumes compare in what magnitude to the annual flow of the "Atlantic Conveyor?" Not quite as great a disparity as throwing tennis balls at oncoming trains, but as far as affecting ocean circulation for centuries? Nerp.

Another problem is the Sea Surface Temperatures in the Cariacio bassin near Venezuela, those plummeted during the Bolling Allerod alleged warm period. If the conveyer had slowed down, then the tropical SST would have risen due to the reduced outflow of heated water.

 

[nannoh]

Iriquois, Candona volumes compare in what magnitude to the annual flow of the "Atlantic Conveyor?" Not quite as great a disparity as throwing tennis balls at oncoming trains, but as far as affecting ocean circulation for centuries? Nerp.

If you have any statistics regarding your statement they might help to substantiate it.

It was not only the Iriquois, Candona volumes dumping into the Atlantic at the time. There had to have been a large number of floods happening during the recession of the Ice Fields. I will try to compile them but I know the information is as rare as the breed of researcher who is doing geological studies of those remaining features caused by the Ice Age Floods.

 

[Bystander]

If you have any statistics regarding your statement they might help to substantiate it.
(snip)

Atlantic conveyor runs around a million cubic kilometers per year, global run-off is around thirty thousand cubic kilometers per year. Slugs of a few thousand cubic kilometers here and there (huge floods) aren't all that significant. Missoula, annual flooding on Nile, or Mississippi, or Yangtze are measured in hundred(s) of cubic kilometers. These are remarkable events if you happen to be living in the run-off path; they aren't remarkable events in terms of the global hydrologic cycle.

 

[nannoh]

Atlantic conveyor runs around a million cubic kilometers per year, global run-off is around thirty thousand cubic kilometers per year. Slugs of a few thousand cubic kilometers here and there (huge floods) aren't all that significant. Missoula, annual flooding on Nile, or Mississippi, or Yangtze are measured in hundred(s) of cubic kilometers. These are remarkable events if you happen to be living in the run-off path; they aren't remarkable events in terms of the global hydrologic cycle.

I can see the disparity between the amounts of water but not the effect temperature change would have on a specific current. It may also be true that the temperature of the floods would not necessarily be much colder than the ocean after sitting as a lake or traveling several hundreds of miles over the surface and in a warming atmosphere.

I also wonder if the introduction of what we see as a large amount of fresh water into a saline ocean would have a slowing or halting effect on the current.

_____________________________

Its interesting how the geologic information gathered about the Ice Age Floods™ is now being used to explain some terrains on mars.

Scientific study of the Ice Age Floods is contributing to the understanding of cyclical climate change and of very large and destructive contemporary floods on Earth. The Ice Age Floods have also been considered as an analog to understand geologic processes on Mars, where landforms strikingly similar to those in Eastern Washington exist.

http://www.iceagefloodsinstitute.org/aboutfloods/relatedphenomena.html

I was back on that site looking for the stats on the volume of fresh water that was released by the disintegration of the ice dams in that region. As I remember it the volume was more like 150,000 cubic kilometres but I can't find the stat. And this was only one reservoir behind an ice dam in the NW.

I think we have to remember that the Ice Fields were commonly 2 miles thick. They covered an area of about 70,000 sq miles. That translates into a lot of melt water even if it melted over 2000 years or more.

 

[Bystander]

(snip)I think we have to remember that the Ice Fields were commonly 2 miles thick. They covered an area of about 70,000 sq miles. That translates into a lot of melt water even if it melted over 2000 years or more.

http://www.gsajournals.org/perlserv/?request=get-document&doi=10.1130%2F0016-7606(2003)115%3C0624:NASOLM%3E2.0.CO%3B2

"Lot of melt water..." 70k x 2 x 4 = 560 k cubic kilometers; 2000 yrs. x 30 k/a = 60 M cubic kilometers. Global runoff is 1% higher during the ice age meltdown? Effects on ocean circulation associated with rising water level are going to be far greater than odd little discharge spikes.

 

[nannoh]

http://www.gsajournals.org/perlserv/?request=get-document&doi=10.1130%2F0016-7606(2003)115%3C0624:NASOLM%3E2.0.CO%3B2

"Lot of melt water..." 70k x 2 x 4 = 560 k cubic kilometers; 2000 yrs. x 30 k/a = 60 M cubic kilometers. Global runoff is 1% higher during the ice age meltdown? Effects on ocean circulation associated with rising water level are going to be far greater than odd little discharge spikes.

Very nice math! I'm not sure that we are calculating the effects of the changes caused by a: fresh water or b: temperature to the system of the Gulf Stream. Simply stating volume vs volume does not look into the
effects of these factors. Is there a text on the effects of fresh water and colder water on warm currents?

 

[Bystander]

Your turn to do the math: come up with a mechanism for stalling the conveyor, and the energy or power necessary to do so that can be derived from excess fresh water runoff.

 

[nannoh]

Your turn to do the math: come up with a mechanism for stalling the conveyor, and the energy or power necessary to do so that can be derived from excess fresh water runoff.

No math yet but there are some factors reported by various research endevours.

These have to do with mineral content in meltwater and its effects on biomass and ocean saltwater but may work somewhat to help or hinder the idea that glacial meltwater can disrupt an ocean current of warmer, denser water. There really didn't seem to be much information specifically pertaining to the focus of this side issue.

http://snobear.colorado.edu/Markw/Research/06_ppp.pdf

And

Finally, the input of meltwater can have a significant influence on the formation of sea ice in this region. In fresher water, the freezing point of water is higher and less energy is required to produce sea ice. Additionally, the amount of stratification in the upper water column also significantly influences the heating and cooling rates of the sea surface. Both the salinity and cooling rate of the surface layer will influence the onset of sea ice formation, which has important implications from oceanographic, climatological, and biological perspectives. Sea ice is an important component of the ocean-atmosphere heat flux and critical to the formation of Antarctic bottom water (17). The annual advance and retreat of sea ice is also a major physical determinant

http://www.pnas.org/cgi/content/full/99/4/1790

And from the same source

Meltwater Interactions Onshore to Offshore. Vertical contours of salinity (Fig. 4 Left) and Chl (Fig. 4 Right) are presented for a transect extending from shore out to 160 km. These example profiles were obtained along the 600 line (Fig. 1A) from five summer cruises (January 1993-1997). Lower salinity is associated with waters close to shore, and salinity gradually increases with distance from shore. Highly stratified meltwater layers extending nearly 100 km offshore are observed in 1995 and 1996. This observation also coincides with the on- to offshore gradient in biomass. The low-salinity surface water is generally mixed between 50 and 80 m within 100 km offshore.

Here's more,

http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/fw/crls.rxml

http://www.viking.no/e/travels/weather/e-current.htm

Some fairly simple models of the world's oceans do simulate a rapid break down of the THC, when the density of the water in the North Atlantic Ocean is lowered by adding fresh water (rain) and/or by warming. Increased rainfall and warming over the North Atlantic are both expected as a result of increased greenhouse gas concentrations, and so it can be argued that global warming may cause a rapid collapse of the thermohaline circulation. The self-sustaining system described above is, however, much more complex in reality, and the more complete climate models, that take some of these complexities into account, generally simulate only a gradual weakening of the THC in response to global warming. Nevertheless, observations and palaeoclimate evidence both indicate that the THC has fluctuated both recently and in the distant past.

http://www.cru.uea.ac.uk/cru/info/thc/

 

[Andre]

There is a problem though with those "meltwater pulses", Here, are three studies that form a big conflict together around a sudden sea level rise that is known as “Melt Water Pulse 1A”. Curiously enough one person, Prof Clark of the Oregon Uni, (co)authored all three of these papers. So I wonder if he wonders about those problems. Let’s start with the most recent one.

Clark et al (2004), http://www.geo.oregonstate.edu/people/faculty/clark_publications/Clarketal.-Science-2004.pdf. Science 21 May 2004: 1141-1144

In which it is shown that clear geologic evidence exists that the great melting at the end of the ice ages started 19,000 years ago, which is a bit odd since the ice cores of Antarctica did not start to show any warming before 17,300 years ago, whilst the Greenland Ice cores waited until some 14,600 years ago. So Clark et al contend:

The initiation of warming at 19,000 years B.P. at Atlantic and Antarctic sites (Fig. 3, D to F) records this expected ocean response to the 19-ky MWP. In particular, we note that warming occurred at Antarctic sites before any substantial rise in atmospheric CO2 (23) and despite a gradual decrease in austral summer insolation.

We have two remarkable things here that the warming began some 2000 years before the CO2 rose, which is held responsible for a large role in that warming and second, that it was Antarctica that warmed and hence started to melt. Let’s keep that in mind when we look at a second study about that Meltwater Pulse 1A.

Weaver A.J. et al (2003) http://www.geo.oregonstate.edu/people/faculty/clark_publications/weaveretal.-science-2003.pdf 14 March 2003 Vol 299 Science pp1710 - 1713

Meltwater pulse 1A (mwp-1A) was a prominent feature of the last deglaciation, which led to a sea-level rise of about 20 meters in less than 500 years. Concurrent with mwp-1A was the onset of the Bølling-Allerød interstadial event (14,600 years before the present), which marked the termination of the last glacial period. Previous studies have been unable to reconcile a warm Northern Hemisphere with mwp-1A originating from the Laurentide or Fennoscandian ice sheets. With the use of a climate model of intermediate complexity, we demonstrate that with mwp-1A originating from the Antarctic Ice Sheet, consistent with recent sea-level fingerprinting inferences…

That’s pretty clear. If you scan the article you’ll see that Clark is amongst the authors and it’s also mentioned again that the warming in the south started as early as 19000 years ago. BTW this is not the only study that gives Meltwater Pulse 1A an Antarctic origin.

Also keep in mind that the current ice sheet of Greenland, central in the public interest, is good for a sea level rise of 7 meters. Apparently, Meltwater Pulse 1A was equivalent to the melting of almost three Greenland ice sheets within 500 years.

But now the third study:

Clark P.U. and Mix A.C (2002)http://www.geo.oregonstate.edu/people/faculty/clark_publications/clark&mix-qsr-2002.pdf, Quaternary Science Reviews 21 (2002) 1–7

We are interested in table 1 about the contribution of the several Ice sheets to the sea level rise. For Antarctica we see a series of 24,5 meters from the oldest studies to 14,0 meters in the more recent studies. Given the fact that there is hardly any tectonic post glacial rebound at Antarctica, that only land ice counts and that there is no room whatsoever to have 2-3 additional Greenland Ice sheets anywhere on the Antarctic continental shelf, 14 meters does seem to be quite a bit already. Now as the melting apparently started 19,000 years ago and lasted several thousand years as the end of the Ice age is marked at 11,600 years ago, you’d expect only millimetres per year from Antarctica but no, it was 20 meters in 500 years, meltwater pulse 1A.

Now this all happened in concert with the high spikes in Greenland, suggesting that it got warmer over there, hence suggesting that the thermohaline current increased in strength, which would also have followed from a sudden and rapid drop of the sea surface temps in the Caracio basin near Venezuela. Did the meltwater pulse increase the thermohaline current?

At this point it could be clear that the reality was much different.

There is a pet idea...

 

[nannoh]

Did the meltwater pulse increase the thermohaline current?

At this point it could be clear that the reality was much different.

There is a pet idea...

I'm not sure what your pet idea is other than the methane release in the eastern Atlantic. But several times there was mentioned the effect of freshwater (meltwater) not mixing with the denser saline waters of the ocean and particularly the Gulf Stream.

The whole effect of the fresh water incursion was to stablize the surface water and for it to stay on the surface. This is where it acts as a "lens" which transfers sunlight into deeper portions of the ocean than usual. And I imagine this lens would not only raise chlorophyll production and biomass numbers but also raise the temperature of the water at that depth. This may have actually agitated the thermohaline current making it stronger, sending it further north at a stronger pace.

 

[Andre]

I'm not sure what your pet idea is other than the methane release in the eastern Atlantic. But several times there was mentioned the effect of freshwater (meltwater) not mixing with the denser saline waters of the ocean and particularly the Gulf Stream.

The essence here is that the meltwater pulse 1A has no source. It's neither from the Northely ice sheet nor from Antarctica. But yet, it was about three Greenland ice sheets in a few decades. Now, out-of-the-box-thinkers would investigate the possiblility that the Meltwater pulse wasn't a meltwater pulse at all, wouldn't you think?

 

[nannoh]

The essence here is that the meltwater pulse 1A has no source. It's neither from the Northely ice sheet nor from Antarctica. But yet, it was about three Greenland ice sheets in a few decades. Now, out-of-the-box-thinkers would investigate the possiblility that the Meltwater pulse wasn't a meltwater pulse at all, wouldn't you think?

Yes.
Something very large entering the ocean causing displacement and consequently sea level rise. (But would also cause a nuclear winter after a global fire storm)

Or
an introduction of magma to the lithosphere causing displacement and the ocean's level rise.

Or methane (primary atmosphere) release?

19,000 you is in the middle/end of the LGM isn't it? Not much would be melting at that point. No Ice Age Floods causing levels to rise.

 

[Bystander]

(snip)The whole effect of the fresh water incursion was to stablize the surface water and for it to stay on the surface. This is where it acts as a "lens" which transfers sunlight into deeper portions of the ocean than usual.(snip)

Fresh water is 3% less dense than sea water --- it floats on the surface --- only so long as there is no mechanical agitation to mix it with seawater (no wind and wave motion --- the situation that holds beneath Arctic pack ice for Canadian shield runoff). Other than that, take a look at the Amazon for effects of 5-7 thousand km³/a fresh water runoff into salt water and "stabilization" of ocean surface. Fresh water does not act as a "lens" in any optical sense; it's generally silt laden (opaque), and is not magically transferring sunlight more deeply into the ocean; it is also laden with nutrients which do enhance biological activity, but, again, this is nothing particularly magical, confers no greater inertia upon water masses that are trivial in comparison to ocean mass to affect major changes upon ocean circulation.

 

[nannoh]

Fresh water is 3% less dense than sea water --- it floats on the surface --- only so long as there is no mechanical agitation to mix it with seawater (no wind and wave motion --- the situation that holds beneath Arctic pack ice for Canadian shield runoff). Other than that, take a look at the Amazon for effects of 5-7 thousand km³/a fresh water runoff into salt water and "stabilization" of ocean surface. Fresh water does not act as a "lens" in any optical sense; it's generally silt laden (opaque), and is not magically transferring sunlight more deeply into the ocean; it is also laden with nutrients which do enhance biological activity, but, again, this is nothing particularly magical, confers no greater inertia upon water masses that are trivial in comparison to ocean mass to affect major changes upon ocean circulation.

I'm not sure why you interpret lenses as magical.

However, I may have misinterpreted the use of the term "lens" in this passage from one of the links I provided above.

A conceptual model for the meltwater input into the system is described below. With solar heating, the snow and ice melts from the glaciers and land surfaces. Being less saline, the runoff enters the water column and creates a lens of fresher water on the sea surface. In the shallow nearshore waters, the resulting lens can be mixed from just a few meters down to 50 m in the water column. The nearshore stations exhibit pulses of freshwater input that occur throughout the growing season (Fig. 2). The salinity of the meltwater lens on the sea surface can be as low as 30.5, but averages around 33.2. Meltwater is more common in the late summer to early fall (January-March).

Under meltwater conditions, the initial radiance reflectance typically increases as more of the light is scattered upward by particles released into the water column. This increased turbidity is likely caused by the presence of highly scattering minerogenic particles that make the waters optically distinct from typical conditions. By station E, 3.7 km offshore, radiance reflectance is half of that at station B (Fig. 3A). Hence, meltwater particles sink out rapidly and are not carried away from shore.

http://www.pnas.org/cgi/content/full/99/4/1790

 

[Bystander]

I'm not sure why you interpret lenses as magical.

I don't. "This is where it acts as a "lens" which transfers sunlight into deeper portions of the ocean than usual," said Nannoh.
(snip)

Tails don't wag dogs. Fresh water runoff doesn't dominate ocean circulation.

 

[Andre]

Yes.
Something very large entering the ocean causing displacement and consequently sea level rise. (But would also cause a nuclear winter after a global fire storm)

Or
an introduction of magma to the lithosphere causing displacement and the ocean's level rise.

Or methane (primary atmosphere) release?

19,000 you is in the middle/end of the LGM isn't it? Not much would be melting at that point. No Ice Age Floods causing levels to rise.

The big sea level rises around the equator (elsewhere it seems to be different) are basically identified in two areas, in the Carribean (Barbados) by dating deep corals, which supposedly have died because of getting too deep due to the rising water and the Indonesian area with inundated mangrove remains (Sunda shelf), following the same logic. In both locations a 20-25 vertical zone dates all the same, 14.5 Ka Cal BP which lead to the conclusion that this 25 meters would have to be flooded in a very short time.

There is the case, data, information and conclusions based on that. The idea is to skip the conclusion and review the data again, realizing that Occam Razor did not work. What else can kill corals and mangroves?

 

[nannoh]

The big sea level rises around the equator (elsewhere it seems to be different) are basically identified in two areas, in the Carribean (Barbados) by dating deep corals, which supposedly have died because of getting too deep due to the rising water and the Indonesian area with inundated mangrove remains (Sunda shelf), following the same logic. In both locations a 20-25 vertical zone dates all the same, 14.5 Ka Cal BP which lead to the conclusion that this 25 meters would have to be flooded in a very short time.

There is the case, data, information and conclusions based on that. The idea is to skip the conclusion and review the data again, realizing that Occam Razor did not work. What else can kill corals and mangroves?

Some sort of exponential bloom of bacteria and algae may have caused the die-off of coral.

http://www.sciencedaily.com/releases/2006/06/060612221839.htm

Extreme volcanic and seismic activity would have a similar effect were it in the proximity of the coral population.

And, perhaps something killed off the tiny crabs that help prevent coral death. (there are going to be a milllion possibilities concerning this topic)

Tiny 'Housekeeper' Crabs Help Prevent Coral Death In South…
(via sciencedaily.com) – Tiny crabs that live in South Pacific coral help to prevent the coral from dying by providing regular cleaning "services" that may be critical to the life of coral reefs around the world, according to scientists from the University of California, Santa Barbara.

http://science.netscape.com/story/2006/10/25/tiny-housekeeper-crabs-help-prevent-coral-death-in-south-pacificI'm reminded of the ruins off the coast of Cuba that were pointed out earlier in this thread. They are reportedly 720 meters below sea level. The question is similar in this case - what caused a rise in sea level of this magnatude? This could be related to your query.

However, my initial reaction to the position of the ruins is that they are out of situ and somehow lost their ground and sank to that depth.

 

[nannoh]

I don't. "This is where it acts as a "lens" which transfers sunlight into deeper portions of the ocean than usual," said Nannoh.
(snip)

Tails don't wag dogs. Fresh water runoff doesn't dominate ocean circulation.

You may be right.

_________________

I would like to look at what effects the Ice Age Floods had on human populations.

If someone has the time they could post scientific data that explores population numbers along the coasts of the world at the end of the Last Glacial Maximum and on how many of these people would have been displaced by a rapid sea level elevation. There is also the factor of the sheer volume of meltwater making its way to the sea across hundreds of miles of land and the effects this would have had on human habitation. These outbursts of meltwater were large scale "land tsunamis" and can easily be imagined as bringing devastating consequences to the established human communities of the time (14,000-10,000 years before present).

Time permitting I'm going to search out data to do with this factor of the Ice Age Floods as well.

 

[Bystander]

(snip)There is also the factor of the sheer volume of meltwater making its way to the sea across hundreds of miles of land and the effects this would have had on human habitation.

Examine the annual floods in the Nile and Amazon basins, and slightly less regular events for other major rivers. You'll find that such events create the habitable conditions for humans.

These outbursts of meltwater were large scale "land tsunamis" and can easily be imagined as bringing devastating consequences to the established human communities of the time (14,000-10,000 years before present).

Not "large scale," and not "devastating" --- the 2004 Xmas tsunami in the Indian Ocean presented the interesting contrast of modern tourist gawking at the stranded fish, and assorted "primitives" heading for high ground on their remote little islands.

Is there a point to your effort to make a mountain of the meltwater molehill?

 

[nannoh]

Examine the annual floods in the Nile and Amazon basins, and slightly less regular events for other major rivers. You'll find that such events create the habitable conditions for humans.



Not "large scale," and not "devastating" --- the 2004 Xmas tsunami in the Indian Ocean presented the interesting contrast of modern tourist gawking at the stranded fish, and assorted "primitives" heading for high ground on their remote little islands.

Is there a point to your effort to make a mountain of the meltwater molehill?

200,000 to 300,000 people died in the Indian Ocean tsunami. In contrast to today's world population that may not seem significant or "devastating". But, in contrast to the world population of 14,000 years ago, people would probably be convinced that their entire world had been wiped out.

My point is simply to explore the ramifications of the Ice Age Floods, be they hypothetical, theoretical or actual. If you think I am pushing biblical stories or alien intervention theories you are mistaken. I am simply fascinated by this rarely studied force of nature and how it has affected the Earth and ultimately mankind.

 

[Andre]

Some sort of exponential bloom of bacteria and algae may have caused the die-off of coral.

However, my initial reaction to the position of the ruins is that they are out of situ and somehow lost their ground and sank to that depth.

We're getting somewhere. So if we can establish that those large alleged sealevel rises were in fact another phenomenon that affected life around the sea levels of the equator.

To get the sunken city also in the picture we could speculate about global reactions to large ice sheets melting, perhaps leaving the Earth in unbalance, being too flat at the poles where the ice sheets no longer pressed the Earth down. Then of course we hypothese about glacial rebounce on a local scale. How about glacial rebounce at a global scale, the complete Earth resettling adjusting the shape to balance gravitational and centrifugal forces. This would also mean a lesser circumference for the equator as the Earth popped back to a more round shape. But water doesn't follow that logic as it always is close to the balanced position. Consequently, as the equator retracted, the water appeared to rise. Could something like that explain the meltwater pulse?

But it's only speculation, we can never know. If we want to prove it, we would need to melt Antarctica.

Another scenario indeed is the large scale methane hydrate events at the Amazone fan area, drastically changing ocean currents, sending massive amounts of cool deep (and indeed less salty) waters to the surface. The proxies confirm both had happened. Corals in not too far away Barbados may not have been happy with that while the global climate changes may have killed off the Mangroves of Indonesia's Sunda Shelf, as it also caused the African Humid Period as well as the extinction of large mammals in North America and Europe, judging to the datings.

So we need no massive flooding without a logical source whereas other scenarios could explain more phenomena.

 

[Bystander]

200,000 to 300,000 people died in the Indian Ocean tsunami. In contrast to today's world population that may not seem significant or "devastating". But, in contrast to the world population of 14,000 years ago, people would probably be convinced that their entire world had been wiped out.

"The entire worlds of 200-300k were 'wiped out.' " If you're interested in human reactions to natural disasters, you might want to start another thread in Social Sciences.

My point is simply to explore the ramifications of the Ice Age Floods, be they hypothetical, theoretical or actual.

They are geologically insignificant. Far larger volumes of soil and rock were moved by the glaciers preceeding the meltdown. Sea level effects on ocean circulation were far larger than those of freshwater runoff. Two and three kilometer thick ice sheets had huge effects on northern hemisphere tropospheric circulation.

If you think I am pushing biblical stories or alien intervention theories you are mistaken.

No one called you a YEC, or a UFO nut case. This thread would be in S&D, or locked were that the case.

I am simply fascinated by this rarely studied force of nature and how it has affected the Earth and ultimately mankind.

It is extensively studied; cirques, kettles, eskers, morraines, and all the other jargon of the ice ages fill texts and journals. It ain't the biggest thing to happen to the planet, or the species. Take a peek at the speculations about the correlations of the Toba event 70ka (?) back, and the mitochondrial DNA "population bottleneck."

 

[nannoh]

Take a peek at the speculations about the correlations of the Toba event 70ka (?) back, and the mitochondrial DNA "population bottleneck."

Thank you for the reference. This is what I'm looking for in terms of contributions to this thread.

Originally I hastily entitled this thread "Ice Age Floods Cause Mass Extinctions?" (as a question) when my main focus was really on the Glacial Flood phenomenon and how it had shaped the terrain of areas on this planet - small scale, large scale or otherwise - and wanted to find out more about it.

However, since the title remained uneditable I did allow some material about species extinction to enter into the discussion. Therefore, whether these floods dealt a blow to the populations and species of the elk or mastadon, humans or phytoplankton of the period the information remained significant to the topic(s) of this thread (as long as its title reads Ice Age Floods cause mass extinctions?). Thanks again for the reference.