Techniques of Geochemical Monitoring

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1. Understand the role of the geochemical monitoring in the scope of volcanic surveillance programmes.

2. Characterize the chemical composition of water in surface and groundwater bodies and to identify and describe the occurring geochemical processes.

3. Understand sampling and analytical procedures for natural waters and volcanic gases, and develop analytical work both in the field and in the laboratory.

4. Characterize the different degassing types found in volcanic/hydrothermal areas, and discuss possible factors that may interfere with the gas emissions.

5. Apply statistical methodologies to model (spatially and temporally) and interpret volcanic gas variations, as well as to recognize the origin of the gases emitted.


1. Geochemical monitoring: main objectives and methodologies; advantages and constrains

2. Hydrogeochemistry

2.1. Types of dissolved constituents and suspended material in natural waters

2.2. Concept of activity, chemical equilibrium and saturation status

2.3. Chemical composition of natural waters and modifying chemical e biogeochemical reactions

2.4. Isotopic tools

3. Sampling and analysing natural waters

3.1. Sampling methodologies

3.2. Methodologies for analyses in the laboratory

3.3. Graphic representation and hydrogeochemistry modelling

4. Volcanic gases

4.1. Types of degassing

4.1.1. Fumaroles

4.1.2. Diffuse degassing

4.2. Origin of the gases

4.3. Factors that influence gas emissions

5. Volcanic gases sampling and analyses in hydrothermal environments

5.1. Sampling strategies for gases from fumaroles and diffuse degassing areas

5.2. Analytical procedures and statistical tools

Teaching Methodologies

Teaching is made through a combination of in-room activities, complemented by the on-line learning platform (Moodle) of the University of the Azores.

Theoretical and practical teaching of the Techniques of Geochemical Monitoring course is based in a succession of complementary classes of both types:

1. Theoretical classes: based in MS PowerPoint presentations, with the development of selected case studies, when applicable.

2. Practical classes: include the resolution of problems and development of water and gas analysis. Two field classes will take place in order to collect water and gas samples and develop several analytical methods.


Albarède, F. (2003) - Geochemistry. An Introduction. Cambridge University Press.

Appelo, C.A.J. & Postma, D. (1993) - Geochemistry, groundwater and pollution. Balkema.

Drever, J.I. (1997) - The geochemistry of natural waters. Surface and ground water environments. Prentice Hall.

Kehew, A.E. (2001) – Applied chemical hydrogeology. Prentice Hall.

Langmuir, D. (1997) - Aqueous environmental geochemistry. Prentice Hall.

Oppenheimer, C., Pyle, D.M. & Barclay, J. (Eds.) (2003) – Volcanic Degassing. Geological Society of London.

Rouwet, D., Christenson, B., Tassi, F. & Vandemeulebrouck, J., (Eds.) (2015) Volcanic Lakes. Advances in Volcanology, Springer.

Selinus, O., Alloway, B., Centeno, J.A. et al. (Eds.) (2005), Essentials of Medical Geology: Impacts of the Natural Environment on Public Health. Elsevier Academic Press.

Sigurdsson, H., Houghton, B., McNutt, S., Rymer, H. & Stix, J. (Eds.) (2015) – The Encyclopedia of Volcanoes (Second Edition), Academic Press.



ECTS Credits



  • Orientação Tutorial - 10 hours
  • Práticas e Laboratórios - 10 hours
  • Teóricas - 10 hours
  • Teórico-Práticas - 5 hours
  • Trabalho de Campo - 10 hours

Evaluation Methodology

  • Exam: 50%
  • Individual and/or Group Work: 50%