Graduate Seminar: Fall 2004 (2 units)
ESPM 298: Weathering, Atmospheric Deposition, and the Biogeochemistry of Soils
CCN 31018
Sec. 2
Thursday 3:30-5 pm 201 Giannini
Ronald Amundson,
Summary
The combined processes of chemical weathering and atmospheric deposition of dust and solutes drive long-term terrestrial ecosystem functioning, and there is a growing interest and research activity in this field. Some of the principle reasons for this expanded interest include the growing use of quantitative chemical mass balance methods (to evaluate net weathering in soils) and a steady increase in the focus on atmospheric transport and deposition as a critical control on soil and ecosystem chemistry. These processes are now being promoted to funding agencies through the Weathering System Sciences Consortium (WSSC)(Anderson et al., 2004. EOS 85(28):265; http://www.wssc.psu.edu/).
The purpose of this seminar is to introduce students to the approaches of measuring weathering rates and amounts in soils, consider the sources of dust and solutes (and their deposition rates), examine on-going research on modeling soil transport and weathering, and review and integrate case studies on weathering vs. time and climate. Additional themes may be explored depending on student interest.
Two introductory meetings will be held: one for class organization and a second as an introductory seminar by the instructor. Subsequent meetings will be coordinated by students and visitors, who will either present an oral discussion and summary springing from assigned papers, or from their own research (within the conceptual context of the seminar). Students will be graded on attendance, presentation of their paper(s), and participation.
The initial organizational meeting will be Thursday, September 2 at 3:30 PM in 201 Giannini. If a time change is needed, it will be decided at that time. A tentative list of topics is given below. The sequence of topics is subject to change.
Aug. 31: Organizational meeting
Sept. 7: Overview of soil formation
Sept. 14: Mass balance models of weathering
Sept. 21: Watershed approaches to weathering
Sept. 28: Global dust sources and patterns
Oct. 5: Behavior of P during weathering
Oct. 12: Behavior of Ca during weathering
Oct. 19: Behavior of S during weathering
Oct, 26: Lessons from chronosequences
Nov. 2: Weathering and hillslopes
Nov. 9: Soil formation in the Atacama Desert
Nov. 16: Plants and weathering
Nov. 30: Weathering and climate
Dec. 7: Integration
Weathering System Science focuses upon the complex interplay of physical, chemical, and biological processes controlling rates and mechanisms of weathering within the Critical Zone -- the zone between the lower limits of groundwater and the outer land and vegetation surfaces. The weathering system is impacted by forcing from tectonism, climate, and anthropogenic activity. The extent and rates of weathering can be read not only in the Critical Zone itself, but also in changes in chemistry in the atmosphere, hydrosphere, and in sediments over geologic time.