Physical Sciences and Mathematics Commons^™

Analyst A: Alternatives In Analysis Of The Utexas1 Surface Wave Dataset, Paul Michaels

Paul Michaels

In February of 2011 an earthquake event caused significant damage and loss of life in Christchurch, New Zealand. Such an event serves as motivation for improved foundation design and characterization of the shallow subsurface. In January of 2013, University of Texas engineers acquired surface wave data which has been made available to the ASCE GeoInstitute Geophysical Engineering Committee for a benchmark project. Participants were invited to process and interpret the common data set. This paper reports the results designated as those of "Analyst A". The active vibroseis and sledgehammer data were combined to produce a composite Rayleigh wave dispersion curve. …

Inferring The Global Cosmic Dust Influx To The Earth’S Atmosphere From Lidar Observations Of The Vertical Flux Of Mesospheric Na, Chester S. Gardner, Alan Z. Liu, Dan Marsh, Wuhu Feng, John Plane

Alan Z Liu

Estimating Unsaturated Hydraulic Functions For Coarse Sediment From A Field-Scale Infiltration Experiment, Michael Thoma, Warren Barrash, Michael Cardiff, John Bradford, Jodi Mead

Jodi Mead

A field-scale infiltration experiment was conducted in coarse conglomeratic soil with high gravel fraction. Unsaturated flow properties were estimated from modeling of infiltration using the van Genuchten–Mualem model and a Metropolis–Hasting optimization scheme. Results provide optimal unsaturated flow parameters for a soil type that is underrepresented for vadose zone flow. Conglomeratic alluvial sediments (sand–gravel–cobbles) are common in fluvial, periglacial, and tectonically active regions but have received little attention with respect to unsaturated flow, specifically moisture–tension–conductivity relationships, due to difficulty in making measurements in the field or laboratory and lack of agricultural value. We used a field-scale infiltration experiment, a one-dimensional …

Evolution Of The Stress And Strain Fields In The Eastern Cordillera, Colombia, Obi Egbue, James N. Kellogg

James N Kellogg

This work integrates stress data from Global Positioning System measurements and earthquake focal mechanism solutions, with new borehole breakout and natural fracture system data to better understand the complex interactions between the major tectonic plates in northwestern South America and to examine how the stress regime in the Eastern Cordillera and the Llanos foothills in Colombia has evolved through time. The dataset was used to generate an integrated stress map of the northern Andes and to propose a model for stress evolution in the Eastern Cordillera. In the Cordillera, the primary present-day maximum principal stress direction is WNW-ESE to NW-SE, …