Currently my research is focused on understanding the causes of climate change. However, I have also worked on many other hydrology topics. I am the Chief Scientist for the WAIS Divide Ice Core project which is studying paleoclimate and ice dynamics in West Antarctica. This NSF funded multi-year multi-institution project will recover an annually resolved climate record that extends ~40,000 years back in time. We will use this record to improve our understanding of why climate changes have occurred in the past and how climate will change in the future. I also make electrical measurements on ice cores to identify annual layers. By counting the annual layers we help determine the relationship between the depth of the ice and the age of the ice. I recently finished a project helping to determining why the water clarity at Lake Tahoe, a large mountain lake on the boarder of Nevada and California, is declining. This involved using an instrumented boat to determine the spatial and temporal distribution of turbidity and chlorophyll concentration in the lake. We also collected the particles responsible for the reduction of clarity and studied them with a Scanning Electron Microscope and Energy Depressive Spectrometry. We found a strong link between urban development and lower near shore water quality. Mineral particles, not algae where the primary cause of the reduced clarity. We also determined that existing regulations are inadequate to maintain the water clarity near the shore. I completed a project in Ghana where we trained the staff of World Vision, an international aid organization, to use aerial photographs and geophysics to identify favorable locations for shallow water wells. By using the methods we suggested World Vision was able to decrease the number of non-productive dry holes by 10 to 50%. World Vision has since expanded their geophysics effort in Ghana by purchasing additional equipment. This effort was funded by the Conrad Hilton Foundation.