DETERMINING RATES OF LANDSCAPE RESPONSE TO TECTONIC FORCING ACROSS A RANGE OF TEMPORAL SCALES AND EROSIONAL MECHANISMS: TETON RANGE, WY

Understanding how mountain landscapes respond to variations in tectonic forcing over a range of temporal scales in active mountain belts remains as a prominent challenge in tectonic and geomorphological studies. Although a number of empirical and numerical studies have examined this problem, many of them were complicated by issues of scale and climatic variability. More specifically, the relative efficiencies of fluvial and glacial erosion, which are presumably controlled by climate, are difficult to unravel. The Teton Range in Wyoming, which results from motion on the crustal-scale Teton fault, is an ideal natural laboratory for addressing this challenge as the tectonic uplift boundary condition and the variation of uplift along strike is well-documented by previous studies and due to its relatively small size, climate can be reasonably expected to vary consistently along strike. Here, we present the results from a study that examines how the Teton landscape responds across the longest (106-7 yrs) and shortest (102-4 yrs) temporal scales. Long-term canyon incision rates determined from apatite (U-Th)/He (AHe) analysis of major drainages are highest (0.24 mm yr-1) where measured uplift rates and duration are highest (near Mount Moran), leading us to propose that tectonic forcing operates as the first order control on long-term Teton erosion. Short-term denudation rates, which are derived by determining sediment volumes in Moran Bay that are deposited in catchments generated during the most recent glacial interval (Pinedale, ~15.5 ka), are 0.00303 – 0.4672 mm yr-1. We compare these rates to previous work, which found that high rock fall rates (1.13-1.14 mm yr-1) deposit large talus volumes in Avalanche and Moran Canyons. Despite their magnitude, such high rates of mass wasting are not sustained over long periods of time, as measured lake sediment volumes (0.007 km3) are. We conclude that the Tetons are transport limited during the interglacial and large volumes of canyon sediment generated during this time cannot be moved absent the advance of valley glaciers. That is, fluvial systems in small mountain systems are substantially less effective than glaciers in denuding mountain topography

Commercial Truck Parking and Other Safety Issues

Commercial truck parking is a safety issue, since trucks are involved in approximately 10% of all fatal accidents on interstates and parkways in Kentucky. Drivers experience schedule demands and long hours on the road, yet they cannot easily determine available parking locations. The objective of this study was to identify information related to parking demand, locations with documented or potential safety issues, and potential countermeasures. The literature review indicated substantial research has been done on commercial vehicle parking, and works have outlined the necessary facilities to accommodate trucks before drivers exceed their allowable hours of driving. Attention to commercial truck parking became a priority with SAFETEA-LU, and this focus continued with the inclusion of Jason’s Law as part of MAP-21. Surveys were conducted to determine how frequently commercial vehicles used parking facilities on interstates in Kentucky. The surveys focused on the state’s two primary north-south interstates (I-65 and I-75). Data samples were also obtained from the other interstates in Kentucky (I-24, I-64, and I-71). Of the 4715 parking spaces surveyed during daytime observations, 2143 were in use, or 45 percent. Of 7,844 parking spaces surveyed during nighttime observations, 6803 were in use, or 87 percent. Crash data were analyzed for the period 2010-2013. Of 848 crashes that were either shoulder-related or fatigue-related, collision reports were reviewed. 239 crashes were related to commercial truck parking. Two-thirds of all crashes included in the analysis occurred on I-75, I-65, I-64, and I-71. Crash cluster locations appeared to be directly related to proximity and usage rate of parking facilities. To address truck parking demand and to improve safety, the following general recommendations were identified in the review of literature: 1) use public and private parking areas to increase capacity, 2) use ITS to improve use of parking facilities, 3) provide realtime information that informs truck drivers of parking facility locations with available spaces, 4) combine GPS tracking with electronic communication to notify truckers of nearest parking, and 5) monitor parking usage rates to determine future needs. Part of the literature review included recommendations from truck drivers. Based on observations at sites on interstates in Kentucky, several locations would benefit from increasing the number of parking spaces, including a number of locations on I-64, I-65, I-71 and I-75. Any site that had 90 percent or more of its spaces used during the surveys could be a candidate for an expansion of existing parking spaces or for development of a new facility to accommodate more parking

Safety Case Workshop

In January 2013, a two-day Safety Case Workshop was conducted in Huntsville, Alabama under the sponsorship of the SAE International G-48 System Safety Committee and A-P-T Research, Inc. (APT). Attendees from industry, government and academia participated, with several making formal presentations on various safety methods. Industry focus is turning to international pursuits, which involve a broader understanding of different approaches to ensuring safety. The United States has typically used a process-based approach in managing system safety programs, but there is a current movement to use the evidence-based Safety Case approach to validate the safety of systems. At the conclusion of the workshop, participants reached the consensus view that the Safety Case approach merits being accepted among the best world-wide system safety practices

Surficial Geologic Map of the Upton 7.5-Minute Quadrangle, Kentucky

The Upton 7.5-minute quadrangle is located south of Elizabethtown along the boundaries between Hardin, Hart, and Larue Counties and within the Mississippian Plateau physiographic region (McDowell, 1986). Topography is characterized by the low relief Pennyroyal plain that sits at altitudes below about 750 ft above sea level, the ridges, spurs, and isolated knobs of the intensely dissected Dripping Springs escarpment; the low relief cap of the escarpment landforms is part of the Mammoth Cave plateau region. Moore (1972) mapped the bedrock geology of the quadrangle, which was later digitized by Toth (2006). Mississippian bedrock is exposed throughout most of the quadrangle and is cut by several northwest-southeast trending vertical faults. The Ste. Genevieve Limestone is the oldest lithology and underlies most of the Pennyroyal region. The Beaver Bend Limestone and Paoli Limestone, Sample Sandstone, and Reelsville Limestone stratigraphic sequence underlie the remaining areas of the Pennyroyal, as well as the lower slopes of the Dripping Spring escarpment. The Beech Creek Limestone, Big Clifty Sandstone, and Haney Limestone Members of the Golconda Formation are exposed along the upper slopes of the Dripping Springs escarpment the upper plains of the Mammoth Cave plateau. The Upper Mississippian Hardinsburg Limestone is exposed on the highest ridges of the Dripping Springs, and the Pennsylvanian Caseyville Formation is locally exposed around the highest peak in the southern part of the Upton quadrangle. Previously mapped surficial deposits include minor areas of alluvium in major tributaries, and “slumped” areas across the quadrangle (Moore, 1972)

Removal of the Northern Paleo-Teton Range along the Yellowstone Hotspot Track

Classically held mechanisms for removing mountain topography (e.g., erosion and gravitational collapse) require 10-100 Myr or more to completely remove tectonically generated relief. Here, we propose that mountain ranges can be completely and rapidly (\u3c 2 Myr) removed by a migrating hotspot. In western North America, multiple mountain ranges, including the Teton Range, terminate at the boundary with the relatively low relief track of the Yellowstone hotspot. This abrupt transition leads to a previously untested hypothesis that preexisting mountainous topography along the track has been erased. We integrate thermochronologic data collected from the footwall of the Teton fault with flexural-kinematic modeling and length-displacement scaling to show that the paleo-Teton fault and associated Teton Range was much longer (min. original length 190-210 km) than the present topographic expression of the range front (~65 km) and extended across the modern-day Yellowstone hotspot track. These analyses also indicate that the majority of fault displacement (min. 11.4-12.6 km) and the associated footwall mountain range growth had accumulated prior to Yellowstone encroachment at ~2 Ma, leading us to interpret that eastward migration of the Yellowstone hotspot relative to stable North America led to removal of the paleo-Teton mountain topography via posteruptive collapse of the range following multiple supercaldera (VEI 8) eruptions from 2.0 Ma to 600 ka and/or an isostatic collapse response, similar to ranges north of the Snake River plain. While this extremely rapid removal of mountain ranges and adjoining basins is probably relatively infrequent in the geologic record, it has important implications for continental physiography and topography over very short time spans

Lightweight transformer

The technical effort described in this report relates to the program that was performed to design, fabricate, and test a lightweight transformer for Strategic Defense Initiative Organization (SDIO) mission requirements. The objectives of this program were two-fold: (1) design and fabricate a lightweight transformer using liquid hydrogen as the coolant; and (2) test the completed transformer assembly with a low voltage, dc power source. Although the full power testing with liquid helium was not completed, the program demonstrated the viability of the design approach. The lightweight transformer was designed and fabricated, and low and moderate power testing was completed. The transformer is a liquid hydrogen cooled air core transformer that uses thin copper for its primary and secondary windings. The winding mass was approximately 12 kg, or 0.03 kg/kW. Further refinements of the design to a partial air core transformer could potentially reduce the winding mass to as low as 4 or 5 kg, or 0.0125 kg/kW. No attempt was made on this program to reduce the mass of the related structural components or cryogenic container. 8 refs., 39 figs., 2 tabs