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The Earth Evolution as a Thermal System

Event Type: 
Event Date: 
07 Sep 2017
EOS Seminar Room - N2-01B-28
C.A. Tang
About the speaker: 

Dr. C.A. Tang, as a chair Professor (funded by Cheung Kong Scholar Programme from State Education Ministry), is the Director of the Center for Rock Instability and Seismisity Research (CRISR) of Dalian University of Technology. He is also the Vice President of the Chinese Society of Rock Mechanics CSRM, and the China National Group Chairman of International Society of Rock Mechanics. In 1984, he started his Ph.D research, in Northeastern University, Shenyang, P.R.China, and got his Ph.D in 1988. In 1991, he continued his post-doctoral work in Imperial College, London, UK. Then, as an academic visitor, he had lots of experience working in Canada, Sweden, Singapore, Switzerland and Hong Kong. He leads several major research projects in rock mechanics, especially on rock failure process analysis and monitoring in civil engineering. He is now appointed as a chief scientist for national 973 program for fundamental researcher (2014 and 2018). His work is funded by the “Trans-Century Training Programme Foundation for Outstanding Young Scholars in China” from the State Education Ministry and by the "Special Natural Science Foundation for Outstanding Young Scholars in China" from National Nature Science Foundation. So far, he has published more than 300 technical papers on rock failure mechanisms and civil engineering, and is the author of six books of rock mechanics and the principal author of “Rock Failure Mechanisms” published by CRC Press, Taylor & Francis Group.

About the event: 

Cooling and warming has occurred many times during the Earth’s history. At times, the Earth has entirely frozen to form a 'snowball’, while at others, it has become extremely hot, resulting in the mass extinction of species. However, despite 50 years of established plate tectonic theory, the reasons that these patterns and extremes of cooling and warming have occurred remain elusive. The speaker proposed a new model of the evolution of the Earth's temperature that explains the planet’s thermal cycles in terms of changes in the heat balance of the system. The expansion of the lithosphere and its associated uplift lead to the collapse of Earth's crust, and volcanism and magmatism are the global-scale response. These shallow lithospheric processes can reach a critical state with a positive feedback loop, resulting in the formation of large igneous provinces, which remove huge heat from lavas by radiating into the outer space. Endothermic phase changes during the de-compressive melting also absorb large quantities of heat from the inner Earth and cool their surroundings. This process may terminate the warming cycle and initiate a new cooling cycle, possibly an ice age.