Physical Sciences and Mathematics Commons^™

Spatiotemporal Slip Rate Variations Along Surprise Valley Fault In Relation To Pleistocene Pluvial Lakes, Brian N. Marion

All Master's Theses

Using mapped paleoshoreline features with high-resolution topographic data and obtained radiocarbon dates on paleoshoreline tufas, I documented precise fault offsets of dated features over the last 25 ka along the Surprise Valley Fault (SVF). Fault offset measured in three lake sections within Surprise Valley ranged from 3.6 m in the southern section to 14.4 m in the central section. The offset paleoshorelines are dated to the late Pleistocene (<22 >ka) and were formed during the latest impoundment of pluvial Lake Surprise since the last glacial maximum. Slip rates vary along strike, assuming a fault dip of 68° with 0.25 ± …

Investigating Taphonomic Changes Of Deposits And Modeling Of The 2010 Earthquake And Tsunami In South-Central Chile, Alexandra Carranco Ruiz

All Master's Theses

South-central Chile has an extensive written catalog of historic earthquakes and tsunamis, but such records can be subject to inconsistencies. Dated tsunami deposits are more objective data that provide hard evidence of past tsunamis. The inland extent of deposits from past tsunamis (paleodeposits) can be used in tsunami modeling to reveal characteristics of the source earthquake, but these deposits may have undergone taphonomic processes since initial deposition. Therefore, to determine how tsunami deposits change during burial and preservation and the potential limitations of using paleodeposits in modeling, I investigated the modern 2010 M_w 8.8 Maule earthquake and tsunami as …

Assessing Shoreline Change And Vegetation Cover Adjacent To Back-Barrier Shoreline Stabilization Structures In Georgia Estuaries, Katherine R. Wakefield

Electronic Theses and Dissertations

Anthropogenic stabilization of erosional shorelines by hard-armoring structures is used for protection of property, especially if buildings, historical monuments, cultural resources, or other infrastructure are present. The post-installation effects of shoreline stabilization structures on adjacent shorelines in the back-barrier marshes of coastal Georgia are a concern, and interest in living shorelines as erosion control devices has increased because of their use of natural materials and vegetation. AMBUR shoreline analysis software was used to calculate pre-and post-installation shoreline change rates of shorelines adjacent to riprap and bulkhead structures. There was no significant difference between the post-installation shoreline change rates of the …

Preservation And Sediment Cycling Beneath "Ghost Glaciers": How Cold-Based Ice Dictates Arctic Landscape Evolution, Lee Corbett

Graduate College Dissertations and Theses

Constraining past episodes of climate change and glacial response is critical for understanding future impacts of climate change, especially in the high latitudes where warming is expected to be rapid and most of Earth's glaciers exist. Many studies of past glacier size utilize rare isotopes called cosmogenic nuclides to perform surface exposure dating. Since most areas of Earth's surface that were previously glaciated were covered by erosive ice, which stripped away pre-existing cosmogenic nuclides, surface exposure dating yields the timing of the most recent deglaciation. However, in some high latitude areas where glacial ice is cold-based and non-erosive (so-called 'ghost …

Erosion Rates In Subtropical, Rapidly Developing Countries: An Isotopic Approach To Measuring Background Rates Of Erosion In Brazil And China, Veronica Sosa-Gonzalez

Graduate College Dissertations and Theses

Erosion, a surface process, can be quantified over long-term (assumed to be the natural erosion rate of the landscape) and contemporary (modern) timeframes. My research used the rare cosmogenic isotope 10Be in sand and cobbles collected from rivers in southeastern Brazil (Santa Catarina and Rio de Janeiro states) and southwestern China (Yunnan province) to quantify long-term, background rates of erosion and sediment supply. These measurements will also increase number of such measurements in tropical and subtropical climates. I assessed the relationship between landscape parameters (topographic and climatic) and background erosion rates in order to understand factors related to erosion.

My …

Late Glacial And Holocene History Of The Penobscot River In The Penobscot Lowland, Maine, Roger Leb. Hooke, Paul R. Hanson, Danile F. Belknap, Alice R. Kelley

Conservation and Survey Division

When the Laurentide ice sheet retreated rapidly (~150 m/a) across the Penobscot Lowland between ~16 and ~15 ka, the area was isostatically depressed and became inundated by the sea. Silt and clay were deposited, but no significant moraines or deltas were formed. The Penobscot River was reborn at ~14 ka when ice retreated onto land in the upper reaches of the river’s East Branch. As isostatic rebound exceeded sea level rise from melting ice, the river extended itself southward. Between ~13.4 and 12.8 ka, it established a course across marine clay and underlying glacial till in the Lowland. Its gradient …

Aquifers Of Nebraska I: The Codell Aquifer In Northeastern Nebraska, Dana Divine, R. Matthew Joeckel, Sue Olafsen Lackey

Conservation and Survey Division

No abstract provided.

New Hampshire Beaches: Sediment Characterization, Larry G. Ward, Kaitlyn A. Mcpherran, Zachary S. Mcavoy, Maxlimer Coromoto Vallee-Anziani

Center for Coastal and Ocean Mapping

The grain size of the natural sediment composing the major New Hampshire beaches under summer equilibrium conditions was determined as a first step in assessing the optimal sediment size that would be needed for beach nourishment. In summer, 2015, seven major beaches including Wallis Sands, Foss Beach, Jenness Beach, North Hampton Beach, North Beach, Hampton Beach, and Seabrook Beach were sampled along three to five transects extending from the dunes or engineering structures (e.g., seawalls) to the low water line. In addition, the beach cross-section was profiled using a rover GPS system or the Emery method (profile rods and the …