Meets: Tuesdays and Thursdays 11 am - 12:15 pm, Benson Earth Sciences 355 Course description: Examines the chemical, biological, geological, and physical processes affecting (and affected by) the chemistry of the oceans. Topics include: chemical cycling in seawater; chemical tracers of ocean circulation; the marine carbon cycle and its interaction with atmospheric CO2; the large-scale interdependence of nutrient distributions and biological productivity; and the chemistry of marine sediments, including early diagenesis. This will be a lecture course. The required textbook is Ocean Biogeochemical Dynamics by Sarmiento and Gruber ('S&G'), with one copy on reserve at Norlin and another at the INSTAAR library. This book will be supplemented by reserve readings from Volume 8 of Treatise on Geochemistry, 2nd Ed. ('ToG') and Schulz and Zabel's Marine Geochemistry ('MG'). Prerequisites: Introductory geology and/or oceanography; CHEM 1111 General Chemistry or equivalent; comfort with algebra and calculus (simple differentials). Grading: 40% homework, 25% midterm exam, 25% final exam, 10% class participation including attendance. Undergraduate and graduate homework assignments and exams will be slightly different, and the two groups will be evaluated separately. Homework: Ten homework assignments will allow students to apply what they have learned in class to practical problems. Math will generally be limited to algebra and basic calculus. Homework assignments are to be handed in during class (generally one week after being assigned), and late assignments will lose 10% credit per day (not per class meeting). If late assignments are left in Marchitto's GEOL mailbox, they must be stamped Received by a member of the office staff during business hours.
Problem Set 1 due 9/15 Exams: Midterm and final exams will include short answer and (for graduate students) longer answer questions, and will stress, but are not limited to, Critical Concepts. The Final will focus on material covered after the Midterm _________________________________________________________________________________ Religious or other obligations: If you have any conflicts with scheduled exams because of religious or other obligations, please notify me at least two weeks in advance of the conflict to request special accommodation. See Registrar's policy on final exam conficts (three on same day). Disabilities: If you qualify for accommodations because of a disability, please submit to me a letter from Disability Services within the first two weeks of class, so that your needs may be addressed. Disability Services determines accommodations based on documented disabilities. Note on academic honesty: Students are allowed to work together on homework problems, but are not allowed to simply copy each other’s work. Copying constitutes cheating under the CU Honor Code. _________________________________________________________________________________ T 8/25: Introduction to marine chemistry and geochemistry Th 8/27: Composition of seawater: Major elements T 9/1, Th 9/3: Catalina Foram Workshop - No Class
T 9/8: Sources, Sinks, & Ions Th 9/10: Internal cycling of elements T 9/15: Tracing upper ocean circulation Th 9/17: Tracing deep ocean circulation T 9/22: Air-sea exchange Th 9/24: Biological primary production T 9/29: Limiting nutrients Th 10/1: Organic matter in the water column T 10/6: Nitrogen and phosphorous cycles Th 10/8: Silicate cycle T 10/13: Midterm Exam
Th 10/15: Carbonate system in seawater T 10/20: Ocean pCO2 Th 10/22: CaCO3 cycling T 10/27: Anthropogenic CO2 invasion Th 10/29: Stable isotopes of C and N T 11/3: Radiocarbon Th 11/5: U-series radionuclides T 11/10:Marine sediments Th 11/12:Pore water chemistry and diffusion T 11/17: Bacterial oxidation of organic matter in sediments Th 11/19: Fe, S, and Mn redox cycles T 11/24, Th 11/26: Fall Break - No Class
T 12/1: Hydrothermal systems Th 12/3: History of ocean chemistry and the rise of cyanobacteria T 12/8: Cenozoic weathering and atmospheric CO2 Th 12/10: Marchitto in Minnesota - No Class
M 12/14 (1:30-4:00 pm): Final Exam
“The chemistry of the oceans is the chemistry of life writ large” -David Archer, U. Chicago
Professor: Tom Marchitto, tom.marchitto@colorado.edu
Office Hours: Thursdays 1-2 pm in Benson 435, or by appointment at INSTAAR
Undergrad enrollment limited to juniors and seniors
3 Credits
Counts toward the Graduate Certificate in Oceanography
Problem Set 2 due 9/22
Problem Set 3 due 9/29
Problem Set 4 due 10/6
Problem Set 5 due 10/20
Problem Set 6 due 10/27
Problem Set 7 due 11/3
Problem Set 8 due 11/10
Problem Set 9 due 11/17
Problem Set 10 due 12/1
Class Schedule, Reading, and Links (subject to change during semester)
Reading assignments are best done before lecture, and include all subsections within a listed section, unless otherwise noted
Click on lecture title for PowerPoint file (available after each lecture, password protected; try refereshing your browser if any links are dead)
introduction, collecting seawater, collecting sediments
No reading
GEOSECS
JGOFS
WOCE
GEOTRACES
principle of constant proportions, salinity, 1-box model, steady state, residence time
Read S&G 1.1
inputs & outputs, periodic tables, d0/d10/transition cations
Read Railsback (2003) accompanied by this table (with more info here)
non-conservative behavior, biological cycling, 2- and 3-box models
Read S&G 1.2-1.3
Nozaki's periodic table of dissolved elements in the Pacific
MBARI periodic table of elements in the ocean
density stratification, ventilated thermocline, tritium, 3He, CFCs
Read S&G 2.3
1st Homework due
water masses, radiocarbon, PO4*, meridional overturning circulation
Read S&G 2.4
Henry's law, stagnant film model, wind speed dependence, 14C and 222Rn methods
Read S&G 3.1-3.3
2nd Homework due
photosynthesis, measurement, nutrient supply, light, biological pump efficiency
Read S&G 4.1
Redfield ratio, trace metal biogeochemistry, Fe fertilization, phytoplankton
Read S&G 4.2 up through "Phytoplankton distribution and productivity," & read "The role of iron" on pp. 160-162
3rd Homework due
POM & DOM, remineralization, AOU & OUR, sinking
Read S&G 5.1-5.2 & 5.4
phosphate, nitrification, denitrification, N fixation
Read S&G 5.3
4th Homework due
diatoms, opal export, silicic acid distribution, Si*
Read S&G 7.1-7.3
electroneutrality, pH, alkalinity, DIC
Read S&G 8.1-8.2
Good book for more details: CO2 in Seawater: Equilibrium, Kinetics, Isotopes by Zeebe and Wolf-Gladrow
Carbonate system calculator (CDIAC)
DIC & Alk distribution, pCO2 systematics, pCO2 seasonality
Read S&G 8.3
5th Homework due
coccoliths/foraminifera/pteropods, CaCO3 solubility, lysocline/CCD
Read S&G 9.1-9.4
global carbon cycle, Revelle factor, ocean acidification
Read S&G 10.1-10.2
Ocean Acidification Network
WHOI Ocean Acidification
6th Homework due
d13C, air-sea d13C, d15N, denitrification
Read C-13 and N-15 sections of Marchitto, 2013
Olsen & Ninnemann (2010)
7th Homework due
decay chains, U-Th dating, 210Pb sed rates, particle tracers
Read sections 6.09.2, 6.09.5-6.09.5.2, 6.09.7-6.09.7.3 of Anderson, 2003
particle size, biogenic, terrigenous, authigenic
Read MG Chapter 1 by Futterer
8th Homework due
pore water profiles, diffusion
Read MG Chapter 3-3.2.3 by Schulz
redox, half reactions, diagenetic sequence, bacteria
Read ToG 6.11.2 by Emerson & Hedges
9th Homework due
seawater redox potential, Fe oxides, pyrite, Mn nodules
No reading
Mn nodules
water-rock interaction, mineral deposits, chemosynthetic ecosystems
Read Vent-Fluid Geochemistry section of ToG article by German & Seyfried
Nautilus Minerals seafloor mining
10th Homework due
banded iron formations, rise of O2 & sulfate, seafloor spreading cycles, cyanobacterial modification of seawater
Read Archean section of ToG article by Lowenstein et al.
CO2 degassing vs. weathering, Sr isotopes, Os isotopes
Read ToG 6.20.3, 6.20.6 by Ravizza & Zachos
Oceans of Change special issue of Science
