Andy Ritchie
Science and Products
Exploring the USGS Science Data Life Cycle in the Cloud
Executive Summary Traditionally in the USGS, data is processed and analyzed on local researcher computers, then moved to centralized, remote computers for preservation and publishing (ScienceBase, Pubs Warehouse). This approach requires each researcher to have the necessary hardware and software for processing and analysis, and also to bring all external data required for the workflow over the...
Characterizing the catastrophic 2017 Mud Creek Landslide, California, using repeat Structure-from-Motion (SfM) photogrammetry
Along the rugged coast of Big Sur, California, the Mud Creek landslide failed catastrophically on May 20, 2017 and destroyed over 400 m of scenic California State Highway 1. We collected structure-from-motion (SfM) photogrammetry data using airborne platforms that, when combined with existing airborne lidar data, revealed that the area exhibited...
Warrick, Jonathan A.; Ritchie, Andrew C.; Reid, Mark E.; Schmidt, Kevin M.; Logan, Joshua B. Geomorphic evolution of a gravel‐bed river under sediment‐starved vs. sediment‐rich conditions: River response to the world's largest dam removal
Understanding river response to sediment pulses is a fundamental problem in geomorphic process studies, with myriad implications for river management. However, because large sediment pulses are rare and usually unanticipated, they are seldom studied at field scale. We examine fluvial response to a massive (~20 Mt) sediment pulse released by...
East, Amy E.; Logan, Joshua B.; Mastin, Mark C.; Ritchie, Andrew C.; Bountry, Jennifer A.; Magirl, Christopher S.; Sankey, Joel B. A regime shift in sediment export from a coastal watershed during a record wet winter, California: Implications for landscape response to hydroclimatic extremes
Small, steep watersheds are prolific sediment sources from which sediment flux is highly sensitive to climatic changes. Storm intensity and frequency are widely expected to increase during the 21st century, and so assessing the response of small, steep watersheds to extreme rainfall is essential to understanding landscape response to climate...
East, Amy E.; Stevens, Andrew W.; Ritchie, Andrew C.; Barnard, Patrick L.; Campbell‐Swarzenski, Pamela; Collins, Brian D.; Conaway, Christopher H. Ecological parameters in the Elwha River estuary before and during dam removal
The Elwha and Glines Canyon dams were removed from the Elwha River in Washington State from 2011 to 2014. We collected data for a variety of metrics in the estuary and on the river delta before (2006-2011) and during (2012-2014) dam removal to assess how increased sediment transport and deposition affected habitats, vegetation, invertebrates, and...
Foley, Melissa M.; Shafroth, Patrick B.; Beirne, Matthew M.; Paradis, Rebecca; Ritchie, Andrew C.
California State Waters Map Series—Offshore of Pigeon Point, California
Introduction In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California’s State Waters. The CSMP approach is to create highly...
Cochrane, Guy R.; Cochran, Susan A.; Cochrane, Guy R.; Watt, Janet T.; Dartnell, Peter; Greene, H. Gary; Erdey, Mercedes D.; Dieter, Bryan E.; Golden, Nadine E.; Johnson, Samuel Y.; Endris, Charles A.; Hartwell, Stephen R.; Kvitek, Rikk G.; Davenport, Clifton W.; Krigsman, Lisa M.; Ritchie, Andrew C.; Sliter, Ray W.; Finlayson, David P.; Maier, Katherine L.
California State Waters map series—Offshore of Scott Creek, California
Introduction In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California’s State Waters. The CSMP approach is to create highly...
Cochrane, Guy R.; Cochran, Susan A.; Cochrane, Guy R.; Dartnell, Peter; Johnson, Samuel Y.; Greene, H. Gary; Erdey, Mercedes D.; Dieter, Bryan E.; Golden, Nadine E.; Endris, Charles A.; Hartwell, Stephen R.; Kvitek, Rikk G.; Davenport, Clifton W.; Watt, Janet T.; Krigsman, Lisa M.; Ritchie, Andrew C.; Sliter, Ray W.; Finlayson, David P.; Maier, Katherine L.
Southern Salish Sea Habitat Map Series: Admiralty Inlet
In 2010 the Environmental Protection Agency, Region 10 initiated the Puget Sound Scientific Studies and Technical Investigations Assistance Program, designed to support research in support of implementing the Puget Sound Action Agenda. The Action Agenda was created in response to Puget Sound having been designated as one of 28 estuaries of...
Cochrane, Guy R.; Cochrane, Guy R.; Dethier, Megan N.; Hodson, Timothy O.; Kull, Kristine K.; Golden, Nadine E.; Ritchie, Andrew C.; Moegling, Crescent; Pacunski, Robert E. Large-scale dam removal on the Elwha River, Washington, USA: source-to-sink sediment budget and synthesis
Understanding landscape responses to sediment supply changes constitutes a fundamental part of many problems in geomorphology, but opportunities to study such processes at field scales are rare. The phased removal of two large dams on the Elwha River, Washington, exposed 21 ± 3 million m3, or ~ 30 million ...
Warrick, Jonathan A.; Bountry, Jennifer A.; East, Amy E.; Magirl, Christopher S.; Randle, Timothy J.; Gelfenbaum, Guy R.; Ritchie, Andrew C.; Pess, George R.; Leung, Vivian; Duda, Jeff J. Sedimentology of new fluvial deposits on the Elwha River, Washington, USA, formed during large-scale dam removal
Removal of two dams 32 m and 64 m high on the Elwha River, Washington, USA, provided the first opportunity to examine river response to a dam removal and controlled sediment influx on such a large scale. Although many recent river-restoration efforts have included dam removal, large dam removals have been rare enough that their physical and...
Draut, Amy; Ritchie, Andrew C.
California State Waters Map Series: offshore of Coal Oil Point, California
In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California’s State Waters. The CSMP approach is to create highly detailed seafloor maps...
Johnson, Samuel Y.; Cochran, Susan A.; Johnson, Samuel Y.; Dartnell, Peter; Cochrane, Guy R.; Golden, Nadine E.; Phillips, Eleyne L.; Ritchie, Andrew C.; Kvitek, Rikk G.; Dieter, Bryan E.; Conrad, James E.; Lorenson, T.D.; Krigsman, Lisa M.; Greene, H. Gary; Endris, Charles A.; Seitz, Gordon G.; Finlayson, David P.; Sliter, Ray W.; Wong, Florence L.; Erdey, Mercedes D.; Gutierrez, Carlos I.; Leifer, Ira; Yoklavich, Mary M.; Draut, Amy E.; Hart, Patrick E.; Hostettler, Frances D.; Peters, Kenneth E.; Kvenvolden, Keith A.; Rosenbauer, Robert J.; Fong, Grace
California State Waters Map Series: offshore of Santa Barbara, California
In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California’s State Waters. The CSMP approach is to create highly detailed seafloor maps...
Johnson, Samuel Y.; Cochran, Susan A.; Johnson, Samuel Y.; Dartnell, Peter; Cochrane, Guy R.; Golden, Nadine E.; Phillips, Eleyne L.; Ritchie, Andrew C.; Greene, H. Gary; Krigsman, Lisa M.; Kvitek, Rikk G.; Dieter, Bryan E.; Endris, Charles A.; Seitz, Gordon G.; Sliter, Ray W.; Erdey, Mercedes D.; Gutierrez, Carlos I.; Wong, Florence L.; Yoklavich, Mary M.; Draut, Amy E.; Hart, Patrick E.; Conrad, James E.; Cochran, Susan A.
California State Waters Map Series: offshore of Carpinteria, California
In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California’s State Waters. The CSMP approach is to create highly detailed seafloor maps...
Johnson, Samuel Y.; Cochran, Susan A.; Johnson, Samuel Y.; Dartnell, Peter; Cochrane, Guy R.; Golden, Nadine E.; Phillips, Eleyne L.; Ritchie, Andrew C.; Kvitek, Rikk G.; Greene, H. Gary; Endris, Charles A.; Seitz, Gordon G.; Sliter, Ray W.; Erdey, Mercedes D.; Wong, Florence L.; Gutierrez, Carlos I.; Krigsman, Lisa M.; Draut, Amy E.; Hart, Patrick E.