My research is focused on the evolution of Earth's surface over human to geologic timescales (tens to millions of years). I study the processes that shape landscapes, including constructive forces like active tectonics and destructive forces like glaciation, river erosion, and landsliding. I approach these problems using a combination of fieldwork, geochronology, remote sensing, GIS, and modeling.

View my CV (pdf)

Jump to a topic:
-PhD: Surface expression of active tectonics in the Himalaya of west Nepal(GO)
-MS: Alluvial records in the southern Colorado Plateau (GO)
-Quaternary history of Lake Clark National Park, Alaska (GO)
-Pre-geology research (GO)

Surface expression of active tectonics in the Himalaya of west Nepal

The central Himalaya exhibit a somewhat uniform topograpic form as one traverses from the foreland into the hinterland. The classic cross-section of the range shows an abrupt rise from the Lesser to the Higher Himalaya. This 4-5 km high mountain front is usually interpreted to be the surface expression of a macro fault-bend-fold where the orogenic wedge is passing over a ramp in the underlying plate boundary thrust.

One striking exception to this model is found in west Nepal, where the mountainfront occurs over two steps, bounding an anomalously low-relief landscape at mid-elevations. Notably, spatial patterns of seismicity get more complicated in west Nepal as well.

For my PhD, I am working on unraveling the along-strike changes in structural geometry, kinematic history, and erosion processes that drive the aforementioned shift in the shape of the mountainfront. My primary tools in this effort include topographic analysis, thermochronology, and cosmogenic radionuclide chemistry. This ongoing work will have important implications for our understanding of regional seismic hazard and our understanding of how orogens evolve. Stay tuned for updates about publications!

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The alluvial records of the southern Colorado Plateau

Streams in the southwestern U.S. are weird. Most of them are dry for most of the year, carrying water only after intense storms or during spring snowmelt. Over centuries, these streams go through cycles of filling with and cutting into the sandy sediments they carry. When a stream is in the 'cut' phase, it is called an arroyo. In the late 19th century, a series of extreme floods initiated the most recent episode of arroyo cutting, causing streams to cut up to 30 meters into their beds. As a result, thousands of acres of farmland were lost to erosion and entire communities had to be abandoned. This regional incision also exposed beautiful cross-sections of alluvial material (in the arroyo walls), allowing us to reconstruct cut-and-fill histories to better understand how these systems respond to changes in climate and land-use.

A classic arroyo of the Colorado Plateau, here ~10 meters deep.

Buckskin Wash is one of these strange, ephemeral streams. Along much of its length it flows through a deep arroyo cut ~10 meters into the valley bottom. It then drains into a slot canyon, where the channel is confined between bedrock walls only meters apart. In alcoves and short expansions within this canyon, tall stacks of sandy deposits are preserved. Previous workers have interpreted these stacks of sand as paleoflood deposits.

Buckskin Wash drains approximately 900 km^2 near the Utah-Arizona border. Its watershed includes the Pink, Grey, White, and Vermillion Cliffs of Utah's 'Grand Staircase'. Truly spectacular country. After diving into the world-famous, 21-km long slot canyon, it goes on to drain into the Paria River, which then drains into the Colorado River just upstream of Grand Canyon.

Flood deposits preserved deep in the Buckskin Gulch slot canyon.

For my Masters thesis, I studied the relationship between these slot canyon paleoflood deposits and the cycles of arroyo cutting and filling that occurred upstream. That work has resulted in a few publications:

Harvey, J.E., and Pederson, J.L., 2011, Reconciling arroyo cycle and paleoflood approaches to late Holocene alluvial records in dryland streams: Quaternary Science Reviews, v. 30, p. 855-866.

Harvey, J.E., Pederson, J.L., and Rittenour, T.M., 2011, Exploring relations between arroyo cycles and canyon paleoflood records in Buckskin Wash, Utah - Reconciling scientific paradigms: GSA Bulletin, v. 123, p. 2266-2276.

More photos of the area here: colorado plateau

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Quaternary geology of Lake Clark National Park, Alaska

Location map for Lake Clark National Park.

While working for the National Park Service, I was tasked with unraveling the Quaternary history of Lake Clark National Park in south-central Alaska. Situated on the west side of Cook Inlet about 130 miles southwest of Anchorage, the park is only accessible by small aircraft. It comprises millions of acres of rugged, glaciated mountains that are drained by countless rivers and waterfalls that feed the bright blue lakes so distinctive of the region. The park is host to two active volcanos (Mt. Redoubt and Mt. Iliamna). Interestingly enough, the day I took the job, Mt. Redoubt erupted with a ~50,000 foot high cloud of ash and smoke.

Very few geologists have worked here, in part because of the inaccessibility, but also because of the relatively complex geology and poor exposure (too much vegetation!). In addition to writing a synthesis report of all relevant research from surrounding areas, I studied the timing of the major glacial advances and retreats that carved out the landscape over the past 30,000 years. I also worked with a geologist from the USGS on a map of the surficial deposits of the park. It is a big project in an even bigger park--my work is only the first of several seasons of effort that will be required to get a handle on its complex geologic history.

More photos of Lake Clark National Park here and here

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Pre-geology research

06/06 - 08/06
Worked as an intern for the NOAA profiler network as part of the Hollings Scholarship program. I got to live in Boulder, CO for a summer and meet a lot of great people. While I enjoyed the work, I was more profoundly touched by the sweet landscapes of the Colorado Front Range.

06/04 - 09/05
Undergraduate research in observational astronomy with Dr. Markus Boettcher. We studied the behavior of 3C 66A, a blazar jillions of miles away. A blazar is a type of active galactic nucleus (AGN). It's where all the mass in a galaxy is slowly getting eaten up by black holes and converted into energy. All this energy shoots out as outrageously powerful jets. Sometimes these jets are oriented so that they point at Earth. We looked at the jet emanating from 3C 66A and how it changed over time. These observations help astronomers understand how these AGN work. To be honest, a lot of the details were over my head...but I did learn a lot in the process. This work got published here: Publication in the Astrophysical Journal in 2005, and in Astronomy and Astrophysics in 2006.

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