SCRIPPS INSTITUTION OF OCEANOGRAPHY FACULTY CANDIDATE SEMINAR: Low Temperature Geochemistry
DATE: April 26th, Thursday, 1p.m.
LOCATION: Eckart Lecture Hall
TITLE: Nonexchangeable d2H of bulk soil organic matter as precipitation proxy?
Hydrogen isotopic ratios (d2H) of water from precipitation have long been used in estimating climate variability as the d2H values of global precipitation have been found to vary systematically with d2H decreasing with increasing latitude, altitude, and continental influence. Despite the wealth of potential climate information stored in bulk soils and sediments, they remain a relatively un-tapped reservoir because of the isotopic heterogeneity and complexity of organic materials accumulating and diagenetic processes occurring in a given soil/sediment as well as the interference of inorganic and mineral hydrogen. However, recent methodological developments have allowed for the analysis of non-exchangeable H (d2Hn) from complex organic matter, such as soils, but it remains unknown how the d2H of precipitation relates to soil organic matter (SOM) d2Hn across global landscapes and at depth in the soil profile. In this talk I will discuss the potential and preliminary limitations of SOM d2Hn as a precipitation proxy.