Stable Isotopes in the Critical Zone
COURSE SUMMARY: This course is graduate-level and will focus on the occurrence, distribution, and behavior of stable isotopes in the Critical Zone, defined as the region between the top of weathered bedrock to the top of the vegetative canopy. The course begins with a very short introduction to the nuclear properties and processes applicable to stable isotopes. Lectures are then devoted to various stable isotope systems, both traditional and emerging. Topics include the hydrologic cycle, plant water use, the carbon cycle, photosynthesis, the nitrogen cycle, enriched isotope studies, isotopes as tracers, and mass spectrometry.
TEXTS: Readings will be distributed to you as pdf files throughout the semester.
Not required, but you may find these books useful:
Principles of Stable Isotope Distribution, R.E. Criss
Stable Isotope Ecology, B. Fry
Principles of Stable Isotope Geochemistry, Z. Sharp
EXAMINATIONS AND CREDIT BREAKDOWN:
Problem Sets (3) 30%
Midterm Exam (take-home) 20%
Final Exam (take-home) 20%
Paper and Presentation 30%
Total 100%
PROBLEM SETS: There will be 3 problem sets assigned at various points in the semester and they will be due the following week. You are welcome to collaborate in groups on these, but your work must be your own.
EXAMS: The midterm and final exams will be take-home and you may use any resources you choose on the exams, but you may not discuss it with your classmates or anyone else.
PAPER AND PRESENTATION: Each student will research a topic related to stable isotopes and their use in the Critical Zone, and write a short (6-8 pages) paper on their findings, and give a 20-minute presentation on their topic during the final exam period for the course. During the semester, we will circulate a sign-up list so there is no duplication of topics. Each student is encouraged to research and present on a topic they find interesting and/or is relevant to their research.
TENTATIVE SCHEDULE:
Week Topic
1 Introduction to stable isotope geochemistry and ecology
Nuclear properties relevant to stable isotopes, thermodynamic equilibrium
2 Terminology and notation, methods for measuring stable isotope abundance
Principles and concepts of stable isotope behavior
3 Hydrogen and oxygen stable isotopes in water and the hydrologic cycle
Global Meteoric Water line, precipitation and terrestrial water isotope patterns
4 Evaporation and its affect on terrestrial water isotopes
Critical Zone stable isotope hydrology: precipitation to groundwater
5 Critical Zone stable isotope hydrology: soil and vadose water
Plant water use and transpiration processes
6 Plant water use and transpiration processes (cont’d)
O isotopes in carbonates: soils, biomaterials
7 Carbonate stable isotope thermometry: conventional and “clumped”
Carbon stable isotopes and the global carbon cycle
8 Photosynthesis and C isotopes
Photosynthesis and C isotopes (cont’d)
9 Organic matter synthesis, transport, decomposition
CO2 production/diffusion in soils, and plants
10 C isotopes in carbonates: soils, biomaterials
Compound- and position-specific C isotope analyses
11 Nitrogen stable isotopes and the global nitrogen cycle
Nitrogen fixation and deposition, soil nitrogen cycle
12 Artificially enriched N isotope studies
Sulfur stable isotope systematics
13 Non-traditional stable isotope systems
Metal stable isotopes as tracers in the Critical Zone
14 Society, the Critical Zone and stable isotopes
Emerging stable isotope topics
15 Mass spectrometry
TEXTS: Readings will be distributed to you as pdf files throughout the semester.
Not required, but you may find these books useful:
Principles of Stable Isotope Distribution, R.E. Criss
Stable Isotope Ecology, B. Fry
Principles of Stable Isotope Geochemistry, Z. Sharp
EXAMINATIONS AND CREDIT BREAKDOWN:
Problem Sets (3) 30%
Midterm Exam (take-home) 20%
Final Exam (take-home) 20%
Paper and Presentation 30%
Total 100%
PROBLEM SETS: There will be 3 problem sets assigned at various points in the semester and they will be due the following week. You are welcome to collaborate in groups on these, but your work must be your own.
EXAMS: The midterm and final exams will be take-home and you may use any resources you choose on the exams, but you may not discuss it with your classmates or anyone else.
PAPER AND PRESENTATION: Each student will research a topic related to stable isotopes and their use in the Critical Zone, and write a short (6-8 pages) paper on their findings, and give a 20-minute presentation on their topic during the final exam period for the course. During the semester, we will circulate a sign-up list so there is no duplication of topics. Each student is encouraged to research and present on a topic they find interesting and/or is relevant to their research.
TENTATIVE SCHEDULE:
Week Topic
1 Introduction to stable isotope geochemistry and ecology
Nuclear properties relevant to stable isotopes, thermodynamic equilibrium
2 Terminology and notation, methods for measuring stable isotope abundance
Principles and concepts of stable isotope behavior
3 Hydrogen and oxygen stable isotopes in water and the hydrologic cycle
Global Meteoric Water line, precipitation and terrestrial water isotope patterns
4 Evaporation and its affect on terrestrial water isotopes
Critical Zone stable isotope hydrology: precipitation to groundwater
5 Critical Zone stable isotope hydrology: soil and vadose water
Plant water use and transpiration processes
6 Plant water use and transpiration processes (cont’d)
O isotopes in carbonates: soils, biomaterials
7 Carbonate stable isotope thermometry: conventional and “clumped”
Carbon stable isotopes and the global carbon cycle
8 Photosynthesis and C isotopes
Photosynthesis and C isotopes (cont’d)
9 Organic matter synthesis, transport, decomposition
CO2 production/diffusion in soils, and plants
10 C isotopes in carbonates: soils, biomaterials
Compound- and position-specific C isotope analyses
11 Nitrogen stable isotopes and the global nitrogen cycle
Nitrogen fixation and deposition, soil nitrogen cycle
12 Artificially enriched N isotope studies
Sulfur stable isotope systematics
13 Non-traditional stable isotope systems
Metal stable isotopes as tracers in the Critical Zone
14 Society, the Critical Zone and stable isotopes
Emerging stable isotope topics
15 Mass spectrometry
