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Full-Text Articles in Physical Sciences and Mathematics
Exploring Links Between Physical And Probabilistic Models Of Volcanic Eruptions: The Soufriere Hills Volcano, Montserrat, Charles B. Connor, R. S. J. Sparks, R. M. Mason, Costanza Bonadonna, S. R. Young
Exploring Links Between Physical And Probabilistic Models Of Volcanic Eruptions: The Soufriere Hills Volcano, Montserrat, Charles B. Connor, R. S. J. Sparks, R. M. Mason, Costanza Bonadonna, S. R. Young
Geology Faculty Publications
Probabilistic methods play an increasingly important role in volcanic hazards forecasts. Here we show that a probability distribution characterized by competing processes provides an excellent statistical fit (>99% confidence) to repose intervals between 75 vulcanian explosions of Soufrière Hills Volcano, Montserrat in September–October, 1997. The excellent fit is explained by a physical model in which there are competing processes operating in the upper volcano conduit on different time scales: pressurization due to rheological stiffening and gas exsolution, and depressurization due to development of permeability and gas escape. Our experience with the Soufrière Hills Volcano eruption sequence suggests that volcanic …
Hydrogeologic Principles Useful In Predicting The Effects Of Stream Flow Alterations On Shallow Groundwater And Associated Riparian Vegetation, Mark Cable Rains
Hydrogeologic Principles Useful In Predicting The Effects Of Stream Flow Alterations On Shallow Groundwater And Associated Riparian Vegetation, Mark Cable Rains
Geology Faculty Publications
Numerous studies have shown that stream water and shallow groundwater are tightly linked in alluvial settings, and that changes in stream stage are propagated rapidly across alluvial aquifers (Castro and Hornberger 1991, Sophocleous 1991). Thus, many researchers have assumed that stream stages approximate water tables in alluvial aquifers (Auble et al. 1994, Stromberg and Patten 1996). This assumption is valid in some cases but invalid in other cases, particularly in arid basin terrain and more humid mountain terrain. Even when this assumption is valid, this relationship only implies correlation and not causation so the potential effects of stream flow alterations …
Melting Processes And Fluid And Sediment Transport Rates Along The Alaska-Aleutian Arc From An Integrated U-Th-Ra-Be Isotope Study, Rhiannon George, Simon Turner, Chris Hawkesworth, Julie Morris, Chris Nye, Jeffrey G. Ryan, Shu-Hui Zheng
Melting Processes And Fluid And Sediment Transport Rates Along The Alaska-Aleutian Arc From An Integrated U-Th-Ra-Be Isotope Study, Rhiannon George, Simon Turner, Chris Hawkesworth, Julie Morris, Chris Nye, Jeffrey G. Ryan, Shu-Hui Zheng
Geology Faculty Publications
A comprehensive data set for young lavas erupted along the Alaska-Aleutian arc is used to examine how fluid and sediment transport rates and melting processes vary in response to systematic changes in subduction rate and dip along the arc and across the ocean-continent boundary. Positive correlations between convergence rate, volcano volume, and 238U excesses suggest that magmatic output is closely linked to the size of the fluid flux which occurred <10 kyr prior to eruption. Sediment-sensitive tracers like Th/Nb, Ce/Ce*, and 10Be/9Be also increase with convergence rate. However, the inferred 10Be/9Be ratio of this component is low relative to that in the incoming sediments, …
Paleomagnetism Of The Mt. Stuart Batholith Revisited Again: What Has Been Learned Since 1972?, Bernard A. Housen, Myrl E. Beck Jr., Russ R. Burmester
Paleomagnetism Of The Mt. Stuart Batholith Revisited Again: What Has Been Learned Since 1972?, Bernard A. Housen, Myrl E. Beck Jr., Russ R. Burmester
Geology Faculty Publications
We have collected 20 new paleomagnetic sites from the Mount Stuart batholith and the adjacent Beckler Peak stock. Using thermal and low-temperature demagnetization, and rockmagnetic tests, we have found that the remanence in most of the batholith is carried by single-domain magnetite. The mean of the new Mount Stuart batholith sites is D = 354.2°, I = 46.2°, k = 87.2, α95 = 4.6°, N = 11, and is similar to those of the Beck and Noson (1972) and Beck and others (1981) studies. Examination of Ar geochronology of hornblende and biotite from the Mt. Stuart batholith finds that the …
Beach Profile Evolution Under Plunging And Spilling Breakers, Ping Wang, Bruce A. Ebersole, Ernest R. Smith
Beach Profile Evolution Under Plunging And Spilling Breakers, Ping Wang, Bruce A. Ebersole, Ernest R. Smith
Geology Faculty Publications
Beach-profile evolution, along with measurements of waves, currents, and sediment concentration, under spilling and plunging breakers of similar height were studied in the three-dimensional Large-Scale Sediment Transport Facility at the U.S. Army Engineer Research and Development Center. Unidirectional irregular waves were generated over a fine-sand beach. Beach-profile shape reached equilibrium after 1,330 and 280 min of spilling and plunging wave actions, respectively. Near the main breaker line, the profile evolved differently under plunging and spilling breakers. Across most of the midsurf zone dominated by surf bores, the equilibrium profile shapes were similar. Uniform energy dissipation per unit volume at equilibrium, …
Evaluation Of The Cerc Formula Using Large-Scale Laboratory Data, Ernest R. Smith, Ping Wang, Jun Zhang
Evaluation Of The Cerc Formula Using Large-Scale Laboratory Data, Ernest R. Smith, Ping Wang, Jun Zhang
Geology Faculty Publications
Longshore transport experiments were conducted in a large-scale physical model to evaluate predictions of the CERC formula with measured longshore sediment transport rates. It was found that the CERC formula produced reasonable estimates if the coefficient K was calibrated and applied to waves with similar breaker type. The calibrated K values are much smaller than values that are commonly used, and there appears to be a strong dependency of transport rate on breaker type. Additional comparisons were made with the formula proposed by Kamphuis (1991). The Kamphuis equation, which includes wave period, a factor that influences breaking, gave good estimates. …
Pre-Drift Extension Of The Atlantic Margins Of North America And Europe Based On Paths Of Permo-Triassic Apparent Polar Wander, Myrl E. Beck Jr., Bernard A. Housen
Pre-Drift Extension Of The Atlantic Margins Of North America And Europe Based On Paths Of Permo-Triassic Apparent Polar Wander, Myrl E. Beck Jr., Bernard A. Housen
Geology Faculty Publications
We reconstruct the relative configuration of North America and Europe prior to separation using paths of apparent polar wander (APW) for the interval 300 to 200 Ma. The Bullard et al. (1965) reconstruction closely superimposes the 300 Ma points on the two APW paths but leaves the 200 Ma points far apart. Conversely, anomaly-based reconstructions for later times approximately superimpose the 200 Ma ends of the paths but leave the older ends far apart. This indicates that separation of the interiors of the two continents began during the interval 300 to 200 Ma, long before surficial rifting commenced in the …