SCEC Award Number 16230 View PDF
Proposal Category Individual Proposal (Data Gathering and Products)
Proposal Title Development of Temperature Proxies in Fault Zones
Investigator(s)
Name Organization
Heather Savage Columbia University
Other Participants N. deRoberts, T. Koczynski
SCEC Priorities 3a, 3b, 3e SCEC Groups Geology, Seismology, FARM
Report Due Date 03/15/2017 Date Report Submitted 11/14/2017
Project Abstract
 Fault temperature rise during earthquakes is a nearly unknown, yet extremely important, parameter in earthquake physics as it dictates whether dynamic weakening mechanisms are activated during earthquake slip. Thermal proxies in the rock record allow for estimates of temperature, and recent work has shown that many chemical reactions take place in fault zones during earthquakes. However without firmly established reaction kinetics, it is impossible to correctly estimate temperature. The aim of this project was to solidify early work on the reaction kinetics of methylphenanthrenes, polycyclic aromatic hydrocarbons that are commonly found in faults that have been buried from 1-4 km.
Intellectual Merit The intellectual merits of this proposal include the refinement of a method, biomarker thermal maturity, for detection of earthquake slip in exhumed faults or drill cores through fault zones. This project represents the first time that we have tested whether biomarker kinetics are affected in real ways by total organic content. The variation in temperature rise across a fault zone will aid our understanding of the earthquake rupture process.
Broader Impacts The broader impacts of this work include the participation of undergraduate and graduate students in the field, as well as a deepening of our understanding of seismic activity along ancient faults.
Exemplary Figure Figure 3. Extracted ion chromatogram showing how heating alters the molecular distribution of methylphenanthrene molecules. Heating for 60 min at 310 °C (red line) increases the abundance of the more thermally stable 3- and 2-methyphenanthrenes (3MP, 2MP) compared to the less stable 9- and 1-methylphenanthrenes (9MP, 1MP) compared to heating at 290 °C (blue line).