California State Polytechnic University
VEPP: Analysis of Inflation-Deflation Events at Pu'u 'Ō'ō Using Tiltmeter Data part of NAGT:Teaching Resources:Volcano Exploration Project: Pu`u `O`o:Examples
Brief three-line description of the activity or assignment and its strengths (you will have an opportunity to expand on this description later in the form): This activity is a homework exercise with an introductory classroom lecture and demonstration component. It may be used in large lecture classes and does not require students to have access to computers in the classroom. Students are asked to use the VALVE interface to retrieve, plot and interpret tilt time series and vector maps for inflation/deflation events at Pu'u 'Ō'ō in the past and possibly present. This is a work in progress, not yet tested in a classroom setting, and examples of a PowerPoint lecture and pdf homework assignment will be uploaded before the start of Spring quarter 2011. All data required is currently already available from the VALVE interface. Full length description: The following activity would be part of a general discussion of the importance of (real-time) volcano monitoring and the different types of tools that are available to geoscientists and the types of signals that may occur prior to eruption events. I personally will be emphasizing the high-tech and near real-time nature of the data/instruments, and the fact that it may also show volcanic processes at work that are not visible to the naked eye. It is essential that the instructor carefully covers the material on The VEPP Tilt Page and the VEPP Inflation-Deflation Example prior to assigning the exercise, and also demonstrates the use of the VALVE interface. The following paragraphs describe the material that should be covered by the instructor in the classroom. Discuss how tilt meters work, using the information on The Tilt Page. Another description of tilt meters can be found at Tunnel tiltmeters, Pozzuoli, Italy. A useful (but possibly time-consuming) activity would be the Building of a Water Tube Tilt Meter. A somewhat shorter alternative demonstration is When will it blow? How a simple tiltmeter can demonstrate the bulging of a volcano before eruption. Discuss the Inflation-Deflation Example, in particular the two animations that show the time series of tilt that are expected for these types of events. In addition to the Kilauea example, possibly show the example of Mount St. Helens. Other useful animations may be found on the IRIS volcano Monitoring page. Show the tilt station location map on The Tilt Page and discuss the meaning of the radial and tangential component in this context. Cover the example Deflation-Inflation (DI) event at the bottom of The Tilt Page. Explain what the graphs show (refer back to tilt station map) and the possible problem associated with heavy rainfall. Use worksheets and Think-Pair-Share questions on graph reading and interpretation. Cover how sensitive these tilt meters are, by discussing the units shown on the plots (microradians), translating them into degrees, and drawing some example angles on the board. Could include the use of the (relatively static) plot on the Kilauea update page to further illustrate the second animation of the time lag of deformation between Kilauea Summit and Pu'u 'Ō'ō, if it shows a DI event at that point in time, or use the following saved image: Demonstrate the use of the VALVE interface by recreating the example graph at the bottom of The Tilt Page in the classroom, show how to use the cursor to select a time window within a time series graph to "zoom in". The homework exercise will incorporate the following questions/assignments: recreate the tilt + rain time series for the example DI event using the VALVE interface (detailed written instructions will be provided, in addition to the notes students should have made during the classroom demonstration, or a Jing-based tutorial might be available from the VEPP website itself) create a similar time series plot for station POO further away from Pu'u 'Ō'ō select only the time period of deflation within this time series and create a vector map for this period showing the tilt for both stations do the same thing for the time period of inflation print out the two maps and draw the location of the Pu'u 'Ō'ō crater on them, based on the map on the The Tilt Page explain the map and the two vectors: do these vectors make sense, both in terms of direction as well as relative length, given the physical process involved (as shown in the inflation/deflation animations in class)? by changing the time period covered by the time series (refer back to classroom demonstration or tutorial on how to change start and end time using interface), investigate a much larger time period and locate at least one other reliable (check the rainfall!) DI event create a tilt + rain time series plot for both tiltmeters for this other DI event, choosing a time scale that will clearly show the entire event, similar to the original plot. Describe why this should be considered a reliable DI event, based on the rain data and a comparison with the original DI event data series. compare and or contrast this DI event in duration and size with the previous event: did it last longer or shorter, was the tilt greater or smaller? Include actual measurements (including units) of both duration as well as size. generate a similar time series plot of tilt and rain for the past week based on the observations of the two DI events, interpret this final graph: is Pu'u 'Ō'ō currently experiencing a DI event? Why (not)?
Quantitative Applications in the Earth Sciences at California State Polytechnic University, Pomona part of Math You Need:Implementations
Instructor: Jascha Polet Enrollment: 10 Challenges to using math in introductory geoscience In this class, as is the case in most of my classes, students have a wide range of quantitative abilities as well as ...