I have had the opportunity to accompany Chris Gentile, a graduate student at UCR on a day trip up to the Hogback landslide in the San Gabriel mountains. He is primarily studying the above mentioned slide in order to date it. To do this, we collected large bags of quartz-rich rock. This rock must be quartz-rich and exposed to daylight for practically the whole day in order for this type of dating to be accurate.

The Beryllium 10 isotope is consistently being built-up in quartz in the rocks by the bombardment of radiation from the sun. By calculating the amount of sun each day throughout the year, we can calculate the amount of Beryllium 10 added to the rock for a given amount of time. Chris uses a digital theodolite on an iPad to do these measurements. This involves pointing the camera towards the peaks of the surrounding mountains at 15° increments in a circle at the point where we collected the rock to be studied.

It was tough to find suitable boulders with surfaces that fit all of the requirements. They must have a surface that has not seen too much weathering and erosion because the face we collect will not be true to its age. The surface must also have abundant quartz, and must not be surrounded by trees or other obstructions that would block sunlight. Another difficulty was actually obtaining the samples. We had to use a rock hammer and chisel to break pieces off to collect.

My internship with Nicolas Barth involves the study of landslides. My main task is to create a geologic map of the Mojave Desert in a program called ArcMap. This requires me to locate and download the .tif files for the given map of an area. Most of these maps are available on the USGS website pictured below:

This is a map comprised of thousands of individual maps. When I click on a location, I can see all of the maps available for that location. Only some maps are relevant to my interest, so I have to choose maps that show small scale surficial features. For many locations, there may be a few thousand maps, but only a handful are useful to me. Below, on the left is an example of the maps available for a location on the map. Below, on the right is my document in ArcMap.

Some maps are not so seamlessly loaded into ArcMap, so in the future, I will learn how to manually georeference a map that does not have the attached georeferencing. Gradually, the map will grow in detail, and this will enable us to locate known landslides on the maps, as well as locate areas of past landslides that may not have been mapped.