Katherine Skalak
Dr. Katherine Skalak studies landscape dynamics and fluvial geomorphology, focused on understanding and predicting changes in the patterns and functions of landforms in response to human impacts and restoration efforts. In particular, dynamics of fine sediment and particle associated nutrients and contaminants on varying temporal and spatial scales, and management effects on fluvial systems.
Dr. Skalak received her undergraduate degree in environmental science from St. Joseph’s University. She received her master's degree in Geology from University of Delaware in 2004. A National Science Foundation GK-12 fellow, she completed her Ph.D in Geological Sciences from the University of Delaware in 2009. She started as a post-doctoral researcher at U.S. Geological Survey in 2009 and became a Research Hydrologist in 2011.
EDUCATION
University of Delaware, Newark, DE. Ph.D. in Geological Sciences, August, 2009
Dissertation Title: "Fine-grained channel margin deposits in a typical gravel bed river: Spatial and temporal controls on the distribution, quantity, and residence time and implications for Centennial-scale Sediment and Mercury Cycling." Adviser: Dr. James E. Pizzuto
University of Delaware, Newark, DE. M.S. in Geology, August, 2004
Thesis Title: “The effects of dams on downstream channel characteristics in Pennsylvania and Maryland: assessing the potential consequences of dam removal.” Adviser: Dr. James E. Pizzuto.
St. Joseph's University, Philadelphia, PA. B. S. in Environmental Science, May, 2001
RESEARCH AND WORK EXPERIENCE
USGS National Research Program. Research Hydrologist, 2011 to present
USGS National Research Program. Post-doctoral research fellow in the Hydroecology of Flowing Waters Project, National Research Program, 2009 to 2011
University of Delaware, Department of Geological Sciences
- Visiting scholar, The Johns Hopkins University, 2006 to 2009
- Research Assistant, January 2005 to June 2006
- Research Assistant, September 2002 to September 2003
- Environmental Management Group, Media, PA. Environmental Consultant, January to August 2002
Biological Treatment Systems, Bala Cynwyd, PA. Lab Coordinator, September 2001 to January 2002
Academy of Natural Sciences, Philadelphia, PA. Research Internship, May to September 2000
TEACHING EXPERIENCE
University of Delaware, Department of Geological Sciences
- Fellow, National Science Foundation’s GK-12 program, June 2006 to 2008
- Teaching Assistant, 2003 to 2004
Science and Products
Direct channel precipitation and storm type influence short-term fallout radionuclide assessment of sediment source
Contemporary fluvial geomorphology and suspended sediment budget of the partly confined, mixed bedrock-alluvial South River, Virginia, USA
Storage filters upland suspended sediment signals delivered from watersheds
Flood effects provide evidence of an alternate stable state from dam management on the Upper Missouri River
Environmental signatures and effects of an oil and gas wastewater spill in the Williston Basin, North Dakota
Head-of-tide bottleneck of particulate material transport from watersheds to estuaries
Geomorphic change on the Missouri River during the flood of 2011
Surface disposal of produced waters in western and southwestern Pennsylvania: potential for accumulation of alkali-earth elements in sediments
Reconstructing suspended sediment mercury contamination of a steep, gravel-bed river using reservoir theory
Large dams and alluvial rivers in the Anthropocene: The impacts of the Garrison and Oahe Dams on the Upper Missouri River
Science and Products
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Filter Total Items: 22
Direct channel precipitation and storm type influence short-term fallout radionuclide assessment of sediment source
Fallout radionuclides (FRNs) and their ratios, such as Beryllium‐7 (7Be) and excess Lead‐210 (210Pbxs), have been used to determine suspended sediment source and age in catchments. These models are based on numerous assumptions, for example, that channel deposition of FRNs from precipitation is negligible in comparison to their delivery to the channel from land surface erosion during individual stAuthorsDiana Karwan, James Pizzuto, Rolf Aalto, Julia Marquard, Adrian Harpold, Katherine Skalak, Adam J. Benthem, Delphia Levia, Courtney Siegert, Anthony K. AufdenkampeContemporary fluvial geomorphology and suspended sediment budget of the partly confined, mixed bedrock-alluvial South River, Virginia, USA
We developed a conceptual model and suspended sediment budget for a 38 km reach of the fifth-order South River, Virginia, for the past 75 yr. Bedrock, terraces, and alluvial fans confine 64% of the channel’s lateral boundaries, while bedrock exposures impose vertical confinement along 37% of the channel. Bedrock exposures in the bed separate pools and riffles developed in gravelly bed material, crAuthorsJames E. Pizzuto, Michael A. O'Neal, Pramenath Narinesingh, Katherine Skalak, Dajana Jurk, Suzann Collins, Jacquelyn CalderStorage filters upland suspended sediment signals delivered from watersheds
Climate change, tectonics, and humans create long- and short-term temporal variations in the supply of suspended sediment to rivers. These signals, generated in upland erosional areas, are filtered by alluvial storage before reaching the basin outlet. We quantified this filter using a random walk model driven by sediment budget data, a power-law distributed probability density function (PDF) to deAuthorsJames E. Pizzuto, Jeremy Keeler, Katherine Skalak, Diana KarwanFlood effects provide evidence of an alternate stable state from dam management on the Upper Missouri River
We examine how historic flooding in 2011 affected the geomorphic adjustments created by dam regulation along the approximately 120 km free flowing reach of the Upper Missouri River bounded upstream by the Garrison Dam (1953) and downstream by Lake Oahe Reservoir (1959) near the City of Bismarck, ND, USA. The largest flood since dam regulation occurred in 2011. Flood releases from the Garrison DamAuthorsKatherine Skalak, Adam J. Benthem, Cliff R. Hupp, Edward R. Schenk, Joel M. Galloway, Rochelle A. NustadEnvironmental signatures and effects of an oil and gas wastewater spill in the Williston Basin, North Dakota
Wastewaters from oil and gas development pose largely unknown risks to environmental resources. In January 2015, 11.4 M L (million liters) of wastewater (300 g/L TDS) from oil production in the Williston Basin was reported to have leaked from a pipeline, spilling into Blacktail Creek, North Dakota. Geochemical and biological samples were collected in February and June 2015 to identify geochemicalAuthorsIsabelle M. Cozzarelli, Katherine Skalak, D.B. Kent, Mark A. Engle, Adam J. Benthem, Adam Mumford, Karl B. Haase, Aïda M. Farag, David Harper, S. C. Nagel, Luke R. Iwanowicz, William H. Orem, Denise M. Akob, Jeanne B. Jaeschke, Joel M. Galloway, Matthias Kohler, Deborah L. Stoliker, Glenn D. JollyHead-of-tide bottleneck of particulate material transport from watersheds to estuaries
We measured rates of sediment, C, N, and P accumulation at four floodplain sites spanning the nontidal through oligohaline Choptank and Pocomoke Rivers, Maryland, USA. Ceramic tiles were used to collect sediment for a year and sediment cores were collected to derive decadal sedimentation rates using 137Cs. The results showed highest rates of short- and long-term sediment, C, N, and P accumulationAuthorsScott H. Ensign, Gregory B. Noe, Cliff R. Hupp, Katherine SkalakGeomorphic change on the Missouri River during the flood of 2011
The 2011 flood on the Missouri River was one of the largest floods since the river became regulated by a series of high dams in the mid-20th century (greater than 150,000 cubic feet per second during the peak). The flood persisted through most of the summer, eroding river banks, adding sand to sandbars, and moving the thalweg of the channel in many places. The U.S. Geological Survey monitored andAuthorsEdward R. Schenk, Katherine J. Skalak, Adam J. Benthem, Benjamin J. Dietsch, Brenda K. Woodward, Gregg J. Wiche, Joel M. Galloway, Rochelle A. Nustad, Cliff R. HuppSurface disposal of produced waters in western and southwestern Pennsylvania: potential for accumulation of alkali-earth elements in sediments
Waters co-produced with hydrocarbons in the Appalachian Basin are of notably poor quality (concentrations of total dissolved solids (TDS) and total radium up to and exceeding 300,000 mg/L and 10,000 pCi/L, respectively). Since 2008, a rapid increase in Marcellus Shale gas production has led to a commensurate rise in associated wastewater while generation of produced water from conventional oil andAuthorsKatherine J. Skalak, Mark A. Engle, Elisabeth L. Rowan, Glenn D. Jolly, Kathryn M. Conko, Adam J. Benthem, Thomas F. KraemerReconstructing suspended sediment mercury contamination of a steep, gravel-bed river using reservoir theory
We use sediment ages and mercury (Hg) concentrations to estimate past and future concentrations in the South River, Virginia, where Hg was released between 1930 and 1950 from a manufacturing process related to nylon production. In a previous study, along a 40 km (25 mi) reach, samples were collected from 26 of 54 fine-grained deposits that formed in the lee of large wood obstructions in the channeAuthorsKatherine Skalak, James PizzutoLarge dams and alluvial rivers in the Anthropocene: The impacts of the Garrison and Oahe Dams on the Upper Missouri River
The Missouri River has had a long history of anthropogenic modification with considerable impacts on river and riparian ecology, form, and function. During the 20th century, several large dam-building efforts in the basin served the needs for irrigation, flood control, navigation, and the generation of hydroelectric power. The managed flow provided a range of uses, including recreation, fisheries,AuthorsKatherine Skalak, Adam J. Benthem, Edward R. Schenk, Cliff R. Hupp, Joel M. Galloway, Rochelle A. Nustad, Gregg J. Wiche - News