GETSI - GEodesy Tools for Societal Issues

Although GPS's first widespread use by geoscientists was to track plate motions, geoscientists have found that GPS can also be used to measure local movement due to changes in the amount of water, snow, and ice. This module guides students to read GPS graphs as scientists do, and use their interpretations of that data to support recommendations that address societal issues related to earthquakes, water resources, and glacier melting. Its flexible use, as in-class group work, homework, and lab activities, provide approximately two weeks of instruction that can be used in sequence, scattered throughout the semester, or used as individual, stand-alone pieces.

Worldwide mass wasting causes hundreds if not thousands of deaths per year and billions of dollars in damages. Many of these losses would be preventable if societies prioritized landslide mitigation. In this 2-3 week module, students use a variety of geodetic and other data to analyze the natural and human characteristics of landscapes that contribute to mass wasting hazards. Most of the geodetic data sets are high resolution topography from Lidar and radar, but some InSAR data are also included. Students consider the environmental and societal impacts of mass wasting and landslides as well as the physical factors behind mass movements. Materials for student reading and preparation exercises, in-class discussions, lab exercises, small group activities, gallery walks, and a final project are provided, as well as teaching tips and suggestions for modifications for a variety of class formats. Case study sites include Peru, Italy, and a variety of North American sites from Alaska to Utah to New York.

In this 2-3 week module, students interpret geodetic data from Greenland to assess spatial patterns and magnitudes of ice mass change and consider mechanisms and timescales for ice mass loss. They also investigate the relationship between ice mass change and global and regional sea level, with an emphasis on the ongoing and future implications of sea level change on civilization. Materials for student reading and preparation exercises, in-class discussions, lab exercises, small group activities, gallery walks, and wall walks are provided, as well as teaching tips and suggestions for modifications for a variety of class formats.

GETSI Field Collection: In this module, students will learn the fundamentals of global navigation satellite systems (GNSS, a more universal term than GPS) and how to apply these techniques beyond answering, "Where am I?" This module teaches how high-precision positioning enables geoscientists to track changes in the surface of the earth that would otherwise be imperceptible. Through brief classroom lectures, demonstrations, and field exercises, students learn both kinematic and static positioning techniques. This module is field-focused, minimizing lectures and computer work and maximizing student time spent designing and implementing surveys as well as analyzing the new data. Most units require half to a full day to execute, although some waiting time may be required for post-processing satellite data.

GETSI Field Collection: Geodetic imaging technologies have emerged as critical tools for a range of earth science research applications from hazard assessment to change detection to stratigraphic sequence analysis. In this module students learn to conduct terrestrial laser scanner (TLS) and/or Structure from Motion (SfM) surveys to address real field research questions of importance to society. Both geodetic methods generate high resolution topographic data and have widespread research applications in geodesy, geomorphology, structural geology, and more. The module can be implemented in four- to five-day field course or as several weeks of a semester course.

This module focuses on the integration of new and emerging geodetic data sets that have revolutionized our ability to understand the processes and fault parameters that control the particular characteristics of a given earthquake. As such, the units provide insight into the fundamentals of fault behavior and the geological record of this behavior as manifest in the geomorphology of the land surface (tectonic geomorphology). Through analysis of this tectonic landscape, students will develop an appreciation that this subject area requires 4-D thinking that is spatial, and temporal considerations as repeated events on a single fault are recorded in the evolution of the surface topography. Additionally, earthquakes have a direct impact on humans through the potential disruption of societal support infrastructure, and the magnitude and location of this disruption can be determined. The module units can be used individually or integrated into traditional laboratory exercises on faults and fault properties and geometries as well as strain analysis that records ongoing deformation. Finally, the module exposes students to a number of digital tools already common at the professional level, including those used to perform modeling of an earthquake.

Measuring water resources such as groundwater and snowpack is challenging, but the advent of satellite gravity measurements and hydrologic GPS applications can augment traditional methods. This module gives students the unique opportunity to learn these newer methods alongside more traditional ones of groundwater wells and SNOTEL stations. They determine the pros/cons, uncertainty, and spatial scales of different methods. Droughts in the High Plains Aquifer and California are used as case studies. In the summative assessment, students pull together what they have learned and write a report with recommendations for policy makers.

Understanding how the Earth's crust deforms is crucial in a variety of geoscience disciplines, including structural geology, tectonics, and hazards assessment (earthquake, volcano, landslide). With the installation of numerous high precision Global Positioning System (GPS) stations, our ability to measure this deformation (strain) has increased dramatically, but GPS data are still only rarely included in undergraduate courses, even for geoscience majors. In this module students analyze GPS velocity data from triangles of adjacent GPS stations to determine the local strain. Students learn about strain, strain ellipses, GPS, and how to tie these to regional geology and ongoing societal hazards. A case study from the 2014 South Napa earthquake helps students make connections between interseismic strain and earthquake displacements.