The unit will investigate the geochemical approaches used to understand the dynamics of the surface Earth, with an emphasis on geochemical archives preserved in ocean sediments. The class will be organised into four themes, each treating a different aspect of surface Earth chemistry and how it is recorded in archives - mainly ocean sediments but also including others ice-cores and loess.
Learning objective
The unit is designed with the particular aim of providing a firm grounding in the geochemical methods used to observe and trace the Earth System, now and in the past. Students will gain a basic understanding of the relevant geochemical techniques through at least one 1.5 hour lecture for each theme, and will encourage students to think about their application and interpretation from first principles. But the emphasis will be placed on independent learning by the student through their own research, and the presentation of that research to the class. For each theme, we will use particular time periods in Earth history as case studies. All students will investigate one of these tools in depth themselves, including the application of that tool to problems and questions in the history of the surface Earth.
Content
The themes covered in the class will include: Tracing the large-scale controls on ocean chemistry through time using analytical tools, mass balance and box models; How ocean physics, chemistry and biology can explain the record of atmospheric chemistry preserved in Quaternary ice-cores; Tracking global-scale aspects of the carbon cycle through time, concentrating on processes on the continents, such as chemical weathering, how their record is preserved in the oceans, and using the Cenozoic as a case study; What secular variation in ocean redox tells us about large-scale biogeochemical cycles, using the Mesozoic as a case study.
Students will be encouraged to become familiar with the range of modern geochemical tools used to investigate key scientific questions within the above themes, such as radiogenic isotopes, stable isotopes, speciation of elements in the oceans and in sediments.
Lecture notes
For lectures on the basic aspects of each theme, slides will be available in advance of the lectures.
Literature
About two thirds of the class will be devoted to student presentations of particular geochemical methods they have researched themselves, with the aid of published papers available online and as guided by the teaching team.
Prerequisites / Notice
This class builds on ETH Bachelors classes in oceanography, in geochemistry and in earth system science. Those who have not taken similar classes in their Bachelors may need to familiarise themselves with basic concepts in order to take full advantage of this class. Basic reading material will be compiled that those who might need them can consult - but it is the responsibility of the student to do the catching up.
Performance assessment
Performance assessment information (valid until the course unit is held again)
Performance assessment as a semester course