Cave reveals Southwest's abrupt climate swings during Ice Age

Jan 20, 2010
Sarah Truebe, a geosciences doctoral student at the University of Arizona, checks on an experiment that measures how fast cave formations grow in Arizona's Cave of the Bells. Credit: Copyright 2010 Stella Cousins.

Ice Age climate records from an Arizona stalagmite link the Southwest's winter precipitation to temperatures in the North Atlantic, according to new research.

The finding is the first to document that the abrupt changes in climate known from Greenland also occurred in the southwestern U.S., said co-author Julia E. Cole of the University of Arizona in Tucson.

"It's a new picture of the climate in the Southwest during the last Ice Age," said Cole, a UA professor of geosciences. "When it was cold in Greenland, it was wet here, and when it was warm in Greenland, it was dry here."

The researchers tapped into the natural climate archives recorded in a stalagmite from a limestone in southern Arizona. Stalagmites grow up from cave floors.

The stalagmite yielded an almost continuous, century-by-century climate record spanning 55,000 to 11,000 years ago. During that time ice sheets covered much of North America, and the Southwest was cooler and wetter than it is now.

Cole and her colleagues found the Southwest flip-flopped between wet and dry periods during the period studied.

Each climate regime lasted from a few hundred years to more than one thousand years, she said. In many cases, the transition from wet to dry or vice versa took less than 200 years.

"These changes are part of a global pattern of abrupt changes that were first documented in Greenland ice cores," she said. "No one had documented those changes in the Southwest before."

Scientists suggest that changes in the northern Atlantic Ocean's circulation drove the changes in Greenland's Ice Age climate, Cole said. "Those changes resulted in atmospheric changes that pushed around the Southwest's climate."

She added that observations from the 20th and 21st centuries link modern-day alterations in the North Atlantic's temperature with changes in the storm track that controls the Southwest's winter precipitation.

"Also, changes in the storm track are the kinds of changes we expect to see in a warming world," she said. "When you warm the North Atlantic, you move the storm track north."

The team's paper, "Moisture Variability in the Southwestern U.S. Linked to Abrupt Glacial Climate Change," is scheduled for publication in the February issue of Nature Geoscience. Cole's UA co-authors are Jennifer D. M. Wagner, J. Warren Beck, P. Jonathan Patchett and Heidi R. Barnett. Co-author Gideon M. Henderson is from the University of Oxford, U.K.

A slice of a stalagmite core before samples are taken from it. The creamy or yellow area upper half of the slice is the region that can be tested to reveal past climate. The reddish, pockmarked region on the bottom half of the slice is the cave-floor rubble the stalagmite started growing on. Credit: Mari N. Jensen, University of Arizona College of Science.

Cole became interested in studying cave formations as natural climate archives about 10 years ago. At the suggestion of some local cave specialists, she and her students began working in the Cave of the Bells, an active limestone cave in the Santa Rita Mountains.

In such a cave, mineral-rich water percolates through the soil into the cave below and onto its floor. As the water loses carbon dioxide, the mineral known as calcium carbonate is left behind. As the calcium carbonate accumulates in the same spot on the cave floor over thousands of years, it forms a stalagmite.

The researchers chose the particular stalagmite for study because it was deep enough in the cave that the humidity was always high, an important condition for preservation of , Cole said. Following established cave conservation protocols, the researchers removed the formation, which was less than 18 inches tall.

For laboratory analyses, first author Wagner took a core about one inch in diameter from the center of the stalagmite. The scientists then returned the formation to the cave, glued it back into its previous location with special epoxy and capped it with a limestone plug.

To read the climate record preserved in the stalagmite, Wagner sliced the core lengthwise several times for several different analyses.

On one slice, she shaved more than 1,200 hair-thin, 100-micron samples and measured what types of oxygen molecule each one contained.

A rare form of oxygen, oxygen-18, is more common in the calcium carbonate deposited during dry years. By seeing how much oxygen-18 was present in each layer, the scientists could reconstruct the region's pattern of wet and dry climate.

To assign dates to each wet and dry period, Wagner used another slice of the core for an analysis called uranium-thorium dating.

The radioactive element uranium is present in minute amounts in the water dripping onto a stalagmite. The uranium then becomes part of the formation. Uranium decays into the element thorium at a steady and known rate, so its decay rate can be used to construct a timeline of a stalagmite's growth.

By matching the stalagmite's growth timeline with the sequence of wet and dry periods revealed by the oxygen analyses, the researchers could tell in century-by-century detail when the Southwest was wet and when it was dry.

"This work shows the promise of caves to providing climate records for the Southwest. It's a new kind of record for this region," Cole said.

She and her colleagues are now expanding their efforts by sampling other cave formations in the region.

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User comments : 28

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hylozoic
1 / 5 (1) Jan 20, 2010
I wonder what proponents of C. Hapgood's Crustal Displacement model (which accounts for Ice Ages by moving different parts of the surface of the planet to the poles, for relatively short periods of time) will make of this information...
Parsec
5 / 5 (1) Jan 21, 2010
Hapgood's model is silliest damn idea I have heard. It would probably describe this as an effect caused by curly cues in the trajectory of movement or some such idiocy.
hylozoic
Jan 21, 2010
This comment has been removed by a moderator.
Benier_Duster
3 / 5 (8) Jan 21, 2010
Hapgood's model is silliest damn idea I have heard. .....


Best keep an eye on Watts page later this year when record global temperatures mean the denialists will need something else to latch on to!
Sancho
1 / 5 (2) Jan 21, 2010
"Climate --- change you can believe in."

DozerIAm
1 / 5 (5) Jan 21, 2010
What are we up to now - 10 consecutive years of global cooling? And there are still you folks that are riding that "hockey stick of doom" chart? Geez. Maybe its time to re-evaluate your beliefs in light of the facts.
rgw
not rated yet Jan 21, 2010
If you have faith, facts are irrelevant.
Loodt
1 / 5 (5) Jan 22, 2010
I didn't know that it was once warm in Greenland. Prof. Dr. Hockey stick Mann doesn't think so. Has this article been PEER-REVIEWED by CREDIBLE AUTHORS?
mosahlah
1 / 5 (1) Jan 23, 2010
Oh, I finally get it. Greenland's ice sheet will melt due to AGW. That will lead to the desalinization event which stops the North Atlantic Current, which stops the transportation of equatorial heat to the arctic, which makes it really cold in Greenland, which leads to.... uh... now I'm confused again. Somebody help me, I'm questioning my faith again.
DachpyarviIe
1.5 / 5 (8) Jan 25, 2010
What are we up to now - 10 consecutive years of global cooling? And there are still you folks that are riding that "hockey stick of doom" chart? Geez. Maybe its time to re-evaluate your beliefs in light of the facts.

Yes, the facts,hmmm http://www.woodfo...00/trend

Now tell me where this mythical '10 years of global cooling" is. Every temperature indicator shows a rising trend over the last decade.
dachpyarvile
1.9 / 5 (9) Jan 25, 2010
This is the real dachyarvile checking in. Now, change the year to 2001 and then show what it says, like this:

http://www.woodfo...01/trend

You will see that most of the trends are downward.

By the way, you are using CRU data again. It is suspect until demonstrated accurate.

And again, the information in the chart is statistically insignificant. Just wanted to make sure I called attention to that.
dachpyarvile
1.7 / 5 (6) Jan 25, 2010
And, if you do this:

http://www.woodfo...09/trend

Note where we would be in this chart and compare our overall statistically insignificant trend in the limited picture with the above link that shows the wider global picture. That it is a global signal is evidenced by comparison of this proxy with other proxy data such as Vostok and so forth.

It also should be pointed out that my comments regarding this decade elsewhere on the site are in relation to the cut-off date of December 31, 2009. Things could change over the next few years as happens in a lot of fields.
dachpyarvile
1.7 / 5 (6) Jan 25, 2010
Whoops! When I edited the post above my link to the proxy data in my second link vanished into thin air. Here it is again for comparison purposes:

http://www.ncdc.n...2000.gif
Skeptic_Heretic
1 / 5 (5) Jan 25, 2010
Didn't they just announce that 09 was the warmest year? The data on the woodfortrees site seems to think otherwise even though they're using the same dataset.
MikeyK
3.4 / 5 (5) Jan 25, 2010
Didn't they just announce that 09 was the warmest year? The data on the woodfortrees site seems to think otherwise even though they're using the same dataset.

No they didn't, 'they' said that 2009 would be amongst the 5 warmest years and that the last decade (the real decade not quackyparviles imaginary friend...sorry decade) was the warmest recorded.
dachpyarvile
2 / 5 (8) Jan 25, 2010
Didn't they just announce that 09 was the warmest year? The data on the woodfortrees site seems to think otherwise even though they're using the same dataset.


Yes, they actually did make that announcement but they modified it shortly after making the announcement, when they noticed errors in the data. It was a smart thing to do, modifying the original announcement. They would have looked like the MET and their repeated falsified predictions had they stuck to their guns.
operator
4.3 / 5 (6) Jan 26, 2010
dachpyvile- seeing your post about the antartic base thats used a lot for ESA space crew training and how you called into question its validity as only being one base on antartica and demamded to see the blue prints, or as you put the "original blue prints not the amended ones" then i reallly do wonder about the saneness of the rest of your posts on here.
you seem to be more of a zealot then those you profess to protest about
MikeyK
3.3 / 5 (7) Jan 26, 2010
Now, change the year to 2001 and then show what it says,
You will see that most of the trends are downward.
By the way, you are using CRU data again. It is suspect until demonstrated accurate.


You seem to be a little unhinged, what you are advocating is to change the data range from arbitrary (the start of the decade)to one that suits you and then you expect us to take you seriously? basically you are artificially 'hiding the incline', something you have been very scathing about previously.
Compound this with you using data, then saying it is worthless, is bizarre. In another post you used a study using proxy data (which you have claimed before is flawed and not useful for the task)to support your view that the MWP was global.
This is a science forum, let us talk about science, could conspiracy theorists find their own little stone to crawl under before they embarrass themselves even mor
MikeyK
3.3 / 5 (7) Jan 26, 2010
It also should be pointed out that my comments regarding this decade elsewhere on the site are in relation to the cut-off date of December 31, 2009.


If you check your graph you will find that, as you probably knew anyway, that the cut-off on the graph, that you have altered the decade, is actually 31st December 2008.
Hmmm, adjusted decade lengths, deceiving information, what is your game?
Skeptic_Heretic
1 / 5 (4) Jan 26, 2010
You seem to be a little unhinged, what you are advocating is to change the data range from arbitrary (the start of the decade)to one that suits you and then you expect us to take you seriously?

Because that hasn't ever been done before, has it.
dachpyarvile
2.1 / 5 (7) Jan 26, 2010
dachpyvile- seeing your post about the antartic base thats used a lot for ESA space crew training and how you called into question its validity as only being one base on antartica and demamded to see the blue prints, or as you put the "original blue prints not the amended ones" then i reallly do wonder about the saneness of the rest of your posts on here.
you seem to be more of a zealot then those you profess to protest about


I am not sure what drew that response. I think you may have me confused with the sockpuppet Dachpyarviie. I am dachpyarvile. The sockpuppet of MikeyK uses a capitalized 'i' to mimic the letter 'l' due to stylesheet setup.

And MikeyK, I do not dispute the proxy data of GISP2, Vostok and so forth. I do dispute what the CRU have done with the proxy data, however.

Nonetheless, I find it fascinating that abrupt climate swings have shown their heads in the actual data.

In addition, both the above incline and decline are statistically insignificant.
MikeyK
3.3 / 5 (7) Jan 26, 2010
Look,
I have nothing to with a 'sockpuppet'. Look elsewhere for your your nemesis. I have been the victim of a 'sockpuppet' with a poster calling themselves 'MikeyK_paid_advovate' accompanied by some unpleasant PM's due to my following the consensus of the vast majority of sane scientists. I suggest you look at different trees to bark up.
Away from the fantasy world and back to the real one, I see you sidestepped the issue of your falsifying and adjusting data to suit your viewpoint. You seem to think everyone else is doing it, why did you do that yourself (strange parallel to the sockpuppet there...if you get my drift..)
Skeptic_Heretic
1.8 / 5 (5) Jan 26, 2010
That's funny, because as a new guy on the site I can speak without bias on the matter, and in my activity I can see who has ranked the comment.
MikeyK | Benier_Duster | Pheiankell | Dachpyarviie | dachqyarville | seem to rank me on every one of my comments, but no one else cares to rank in any direction, all within a relatively short span of time. It appears you are the puppet master, or working with him to prevent conversation on topics you are opposed to. I've seen this sort of activity before, now we just need a statement from you that "the science is settled".
MikeyK
3.4 / 5 (5) Jan 26, 2010
Dachpy/skeptic you are not kidding anyone, quit playing stupid games and start talking about science. For obvious reasons do not immerse me in your fantasy world of sockpuppets.
Skeptic_Heretic
1 / 5 (5) Jan 26, 2010
skeptic you are not kidding anyone, quit playing stupid games and start talking about science.

That's what I've been doing. If you disagree, let's talk about it. Put your clone army to bed and try to resist clicking any number of stars for a little bit and let's see where we can come to common understanding.
MikeyK
3.4 / 5 (5) Jan 26, 2010
Skeptic, so at last you admit to being a dachpy/vela/phel sock puppet...it's a start..
dachpyarvile
2.1 / 5 (7) Jan 26, 2010
I for one would like to see where he admits to anything of the sort. For the last little while you have done nothing but misread people's posts and even considerable other materials. This is indicative of a comprehension problem that can be remedied by proper assessment and treatment.

Aside from this, however, I find it of much interest that the Southwest had abrupt climate swings during the Ice Age. I find this of interest and hope that more studies of the above nature will be done. More to the point, it would be of interest to compare some of the data at the present time to that of the past Ice Age.
MikeyK
3.4 / 5 (5) Jan 27, 2010
Skeptic, so at last you admit to being a dachpy/vela/phel sock puppet...it's a start..


i think you have just confirmed it again by your response..do you spend a lot of time talking to yourself in mirrors then blaming everyone else for doing it?
Skeptic_Heretic
1.8 / 5 (5) Jan 27, 2010
I think you need to try harder in terms of your obfuscation.

Upset I didn't include an l or capital I in my name?