For my doctoral research, I worked with Drs. Joel Johnson (Univ. of Texas), Nicole Gasparini (Tulane), and Leonard Sklar (Concordia) on a field-based study across the Kohala Peninsula on the Big Island of Hawai‘i. Exploiting a dramatic spatial gradient of precipitation, I found that increases in rainfall can promote chemical weathering, and consequently, physically weaken rocks exposed in ephemeral streambeds (Murphy et al., Nature, 2016). This means that rivers in wetter regions are able to more easily and rapidly erode their bed, which we found results in different rates and patterns of river erosion across this volcanic island (Han et al. [including Murphy], 2014; Murphy et al., 2016).
This research highlights one mechanism by which variations in climate can influence the evolution of bedrock rivers. These rivers set the erosion rate for the surrounding landscape in many steep, mountainous regions of the world, thus continuing to study and quantify climate-erosion relationships is integral to better predicting the complex feedbacks between climate, erosion, and tectonics in actively uplifting mountain belts.