The Mysteries of the Mammoth Mega fauna

[Andre]

Just playing with alliterations a bit. Looks better. What I would like your opinion about is some mysteries that seem to encompass the Mammoths.

The remains of mammoths and other mega fauna has puzzled mankind for centuries now and was fueled with new impulses when the http://www4.nau.edu/amqua/v29n2/jarkov_mammoth.htm was found a few years ago.

Are mammoths (ice age survival and extinction) a real mystery or can we explain it simply? Could they have survived in a arctic tundra or was the climate different? Why do we find frozen mammoths? What has happened?

Any thoughts?

 

[eNtRopY]

Like the bomber jacket, mammoths went out of style. Don't worry they'll probably come back sooner or later.

eNtRopY

 

[Bubonic Plague]

I've always thought that mammoths were hunted to extinction by humans.

Could you elaborate on your points? I can't really see where you are going.

 

[Andre]

Let's concentrate on climate

There are two 'mysteries' related to the Mammoths. Why did they become extinct? Kill, ill or chill, and climate. Since I was attempting to explain why there is no human made global warming, I would like to concentrate on climate first.

We do have the scientific report of the Yarkov Mammoth. The formal one on the web is protected so we found another source http://hanskrause.de/HKHPE/index%20HKHPE%2021%2000.htm

Don't pay attention to the conclusions of the page owner. He is digressing. Concentrate on the scientific report:

A few quotes:

The Jarkov-mammoth dates from 20,380 year ago. That means that it lived during the coldest period of the last Ice Age….

….The overall picture based on interpreting these fossils, is a landscape dominated by a steppe vegetation as a consequence of dry and cool climatic conditions. Moreover, pollen diagrams produced recently from lake deposits elsewhere in the Taimyr area demonstrated that vegetation during the Late Weichselian glacial maximum was typical for a steppe. …..

..The present climate at or near 80°N on dry land, the average from 6 stations, is 3.88°C mean July air temperature. 103.5 mm annual precipitation. 1.5 kcal.m²l mean net radiation at earth’s surface per year. 25.4 mm potential evapotranspiration. 0 meter height of climatic snowline (at sea level). –17°C mean annual air temperature (just like annual air temperature of sea ice). Thick permafrost and growing ice wedges……

On the other hand, let's look at that Last Glacial Maximum. What is the current idea of climate specialist http://www.esd.ornl.gov/projects/qen/nercEURASIA.html . He does not particulary cover the period of 25-18,000carbon years BP but about Siberia during the LGM, that includes 20,000 years BP he tells us:

Conditions all across northern Eurasia appear to have been dry and treeless, dominated by polar desert or semi-desertic steppe-tundra…..

In the coldest parts of north-eastern Siberia, Frenzel suggests winter that temperatures were some 12-14 degrees lower even than the present extreme temperatures. Summer temperatures for August (Frenzel 1992b) are reconstructed as being about 6 deg.C lower throughout Siberia and the central Asian desert region, except in the north-west close to the ice sheet where they may have been 8-10 deg.C lower than today…..

…..Large ice-dammed lakes appear to have been present in the west Siberian basin throughout the full glacial period (Velichko and Kurenkova 1990).

The Jarkov Mammoth was found in the North west part of Siberia hence it was 8-10 degrees colder hence, the mean maximum temperature was 3,88 – 8-10°C = about –5°C always below freezing. So how did the Jarkov mammoth live there and who smuggled that arid steppe in that area?. So appears that Siberia was a lot warmer when the Earth was suffreing from the coldest part of an ice age?

How about global warming if we can't even get a clear picture of global cooling in the recent past.

Gentlemen Quartenary Geology PhD's You got yourself a riddle to solve. Any of you in for a discussion?

 

[Phobos]

In general, I hear that it's still a bit of a mystery/debate as to why so many mega-fauna species (of which mammoths were but one kind) became extinct. Climate change is definitely one big possibility. There also seems to be a good correlation between the arrival of humans into a region and the end of such species (e.g., Australia, the Americas, etc.). Coincidence? Maybe, maybe not. I would personally suspect a combination of factors...environmental problem compounded by human predation. Given the low population levels at that time, I doubt that humans could be the sole reason for those species' extinction.

 

[Bubonic Plague]

Gentlemen Quartenary Geology PhD's You got yourself a riddle to solve. Any of you in for a discussion?

I'll chip in when the weekends arrive, 'cause during weekdays, i'll be too pooped out from school to be able to concentrate on this mystery.

 

[Andre]

About the extinction, Phobos. You could argue that in America the megafauna became extinct due to human population coming up (the kill) but that does not explain the extinction in Siberia, where man was supposed to be around much longer. It has been speculated that a disease may have done it http://www.rcsd.k12.ms.us/~web08/bhs_main/teachers/WEB_JHOLLIS/mammoth2.htm but diseases need a vector to spread rapidly enough to do such a thing world wide and there were no airplanes then. Climate change is possible, http://www.outriderbooks.com/ot10.html as it can be argued that it became colder in Siberia in the last 15,000 years. But America warmed up in the same time. Besides, animals tend to migrate to the best place to live.

Also interesting is that Mammoths continue to roam on http://geography.berkeley.edu/ProgramCourses/CoursePagesFA2002/geog148/Term%20Papers/Anita%20Lee/DISCUS~1.HTM#Wrangel

There might be a fourth reason but I´m not ready to elaborate, need more research first. Anyway again the point that I wanted to make is the climate. When America got rid of the deep freeze ice age, Siberia went from a animal steppe to a deep freeze tundra, suggesting that the total Earth temperature may not have changed so much at all between 20,000 and 10,000 years ago, when the last ice age ended.

 

[Phobos]

Thanks for the links, Andre. I'd need to check into the details, but I suspect the human presence in Siberia was slow to build (slow to become a serious extinction threat for other species). Anyway, I'm just speaking from my general impressions. I'll take a look at those links and see if I can dig up some other info too.