A Weak Sun Possibly Brought Down The Tang Dynasty & Mayan Civilization
Tomorrow’s issue of Science hosts lots of interesting papers, one of which is titled, “A Test of Climate, Sun, and Culture Relationships from an 1810-Year Chinese Cave Record,” and reports on the analysis of a 1.2-meter-long stalagmite from Wanxiang Cave in northern China. The analysis tells us that the rock holds records of waning Asian monsoon rains around 1,100 years ago. The dry spell was due to weakening of the sun, possibly from a sunspot, and this climate change is thought to have been what brought down the Tang dynasty.
Map of Wanxiang Cave, China
Stalagmites are calcium carbonate mounds which form from dripping groundwater. Chemical analysis of this Wanxiang stalagmite told the researchers that there’s a lot of uranium and exceptionally low clay-borne thorium. That allowed them to do a uranium-thorium radiometric dating of the layered deposits down to an interval of 2.5 years. With such accuracy, the authors were able to calculate precise dates for variations in the stalagmite’s oxygen isotope composition. Oxygen isotope levels reflect variations in rainfall near the cave. The isotope levels match that of drought conditions.
Comparing this result to Chinese historical records of rainfall, the authors matched the chemical analysis to the written record. Furthermore, previously published climate record from a lake on the southern coast of China also confirm this. This 9th-century dry period is also thought to be what also doomed the Mayan civilization. Poor rainfall affected crops and the carrying capacity of each civilization.
- P. Zhang, H. Cheng, R. L. Edwards, F. Chen, Y. Wang, X. Yang, J. Liu, M. Tan, X. Wang, J. Liu, C. An, Z. Dai, J. Zhou, D. Zhang, J. Jia, L. Jin, K. R. Johnson (2008). A Test of Climate, Sun, and Culture Relationships from an 1810-Year Chinese Cave Record Science, 322 (5903), 940-942 DOI: 10.1126/science.1163965
This is invaluable research – thanks.
I suspect we will have many more climate/history conclusions, including the one we’re going through now.
richardparker01@yahoo.com
November 6, 2008 at 5:48 pm
[...] know you didn’t think of this before: a weak sun may have brought down the Mayans as well as China’s Tang dynasty (Subscription required if [...]
Tiny Planet » Links o’ the day 10/11/2008
November 10, 2008 at 4:47 am
This seems silly to me.
Also, what’s up with all the authors being chinese except for the final author, a westerner. This seems to be the new trend from chinese researchers. It’s so obvious what you are trying to do. I guess the main author figured right, that to get this junk published they need to tag a token white guy to give it “legitimacy” for a journal.
John Kim
December 15, 2008 at 6:07 pm
@ John Kim. Not too bright, are you son? There’s an irony there, if you can spot it. ;-)
Dr. Sean Coyne
July 13, 2009 at 7:36 pm
Also, John Kim, the Chinese and Japanese have been winning Nobel prizes since it’s inception. Glad you aren’t in charge of anything!
DaveA
August 4, 2009 at 6:24 pm
Dr. Sean Coyne, fucking classic my friend.
Erick Covarrubias, PdH
August 10, 2009 at 3:26 pm
Dr.’s Erick and Sean,… nice…I’m still laughing.
John
September 28, 2009 at 9:52 am
Common sense should dictate that when you can’t feed a population it will die. Stay tuned as this advancing population, growth, and climate change becomes history, evident to this truth.
Pete
October 20, 2009 at 10:56 pm