This Student Rocks!

Sean Thatcher, Class of 2017, majored in Biology and minored in Geology

I wanted to understand the fascinating dynamics between the biological and physical environments. In the fall 2015 semester I took the course Geologic Hazards and Natural Disasters to understand how the geology, geography, and land use practices could effect the severity of natural disasters found in regions worldwide. In this course and the associated lab, emphasis was placed on understanding the natural disasters prone to effect Staten Island, such as slope failure, hurricanes, storm surges, stream processes, flooding, and climate change. 

Typically students utilize the Arthur Kills & Narrows Quadrangles, topographic maps showing land use, elevation, street names, buildings, etc., with knowledge from the the lecture to create a hazards assessment for Staten Island. Because of my quadriplegia from  a swimming accident, drawing on paper maps can be cumbersome at best. To compensate for my physical limitations and complete the same projects as the other students in my class, I created the same hazard assessment maps using Google Earth Pro.

Google Earth was released to the public in 2005 and allowed people to use satellite imagery to view their homes, businesses, or various other locations. An advanced version of this program, Google Earth Pro, was also released at a cost of $400, with advanced tools allowing for digital map overlays, creating paths, adding various polygons, and even the ability to create animations. This allows the user to connect geospatial data to various locations, have measurements such as area and distance, and key geodetic information without using more complicated programs, like ArcGIS, that would confuse novice users without additional instruction.

This year Google Earth Pro was released free of charge to download to your personal PC, allowing everyone the opportunity to gain experience with this basic geographical imaging system (GIS). To begin developing the desired maps for this course I connected the Earth Point Topographic Map, free of charge from the United States Geological Survey, which provided me access to topographic maps across the United States. By using the zoom and toggle features I could easily observe the topography from the map super imposed on the elevation data provided in the program. This process made it very intuitive to understand how the surface geology, when a map of Staten Island surface geology was added as an image overlay, could effect the the topography of the area based on its susceptibility of the formations to withstand erosion. For example, the Staten Island serpentinite, a geologic formation composed of metamorphic rock from the Ordovician, is highly resistant to erosion, causing this formation to be associated with the highest elevation points on Staten Island, specifically Todt Hill.

Because of the high elevations and steep slopes associated with serpentinite on Todt Hill, this is highly susceptible to slope failure if the area is experiencing large precipitation amounts or alterations in slope steepness due to human construction. By using the topographic map and tracing the areas where the contour lines are close together using the polygon tool, it is possible to create a visual representation of the areas most prone to slope failure. To examine this further, by adding a "path" and using the "show elevation profile" option, it is possible to create an image of the topography to clearly identify specific locations at risk if an event of slope failure were to occur.

Of most interest to me was the in-depth look of coastal hazards on Staten Island from erosion, sea level rise, and storm surges. On the topographic map we identified areas where groins, hard structures built from the sandy portion of a beach into the water to trap sand and prevent beach erosion were in 1981. By comparing this information with present day satellite imagery from Google Earth Pro, it clearly shows areas actively being eroded today by littoral drift, erosion from wave activities in high energy beach environments, and human activities. As these sandy beach areas recede from erosional forces, the human communities behind them become more threatened due to ocean inundation from sea level rise and storm surges associated from extreme weather events. 

It is also possible that these areas are receding because of rising sea levels, which are expected to increase by approximately 1.0 m this century. By tracing the 10' and 20' contour lines around Staten Island, it is easy to visualize the threats our community faces in the wake of climate change if sea levels rise by this projected amount and are coupled with storm surges. When observing the generated maps and comparing them to the redesigned flood zone maps on Staten Island, it is interesting to observe how closely related they are, especially the 20' map. Because of the threats, our community, and communities worldwide, face from the dangers of rising sea levels. My own research interests have developed in understanding coastal ecosystems and the key role they will play in protecting human communities by providing natural defenses from flooding.

By utilizing GIS programs, like Google Earth Pro (and ArcGIS for those with more experience), students can grasp an in-depth understanding on how local geology can effect the topography and natural hazards that their communities face. By using spacial data, students can think more analytically and quantitatively of the world around them to better create plans for urban development, ecological restoration, and grasp a deeper understanding of the threats facing our communities from climate change. By utilizing Google Earth Pro I have decided to pursue a deeper understanding of GIS programs, and learn to develop models to better enhance our understanding of physical and ecological dynamics.