The authors demonstrate an efficient room temperature source of terahertz radiation using femtosecond laser pulses as a pump and GaAs structures with periodically inverted crystalline orientation, such as diffusion-bonded stacked GaAs and epitaxially grown orientation-patterned GaAs, as a nonlinear optical medium. By changing the GaAs orientation-reversal period (504–1277 μm), or...
Temperature‐depth data from six boreholes in western Utah and nine boreholes in southeastern Utah are reanalyzed for evidence of ground surface temperature (GST) histories. We invert the temperature‐depth data using the functional space inverse algorithm of Shen and Beck [1991, 1992] which we prefer over previous inversions of these data...
We construct a mid-latitude (30° – 60° N) reduced temperature-depth profile from a global borehole temperature database compiled for climate reconstruction. This reduced temperature profile is interpreted in terms of past surface ground temperature change and indicates warming on the order of 1°C over the past 100 to 200 years....
We construct an extratropical reduced temperature–depth profile for land areas north
of 20°N latitude from the global borehole temperature database compiled for climate
reconstruction. The mean reduced temperature profile compares well with a time series
constructed from an initial baseline temperature (0.6° ± 0.1°C) and the last 140 years
of...
Temperature profiles from boreholes on the Colorado Plateau of southeastern Utah have been examined for evidence of climate change. Because these boreholes penetrate layered sedimentary rocks with different thermal conductivities, Bullard plots (temperature versus integrated thermal resistance) are used to estimate background heat flow and surface temperature intercepts. Reduced temperatures,...
Long-period ground surface temperature variations contained in borehole
temperature-depth profiles form a complementary climate change record to high-frequency,
but noisy surface air temperature (SAT) records at weather stations. We illustrate the
benefits of jointly analyzing geothermal and meteorological data for two regions in Utah
where both high-quality temperature-depth measurements and...
Temperature profiles from boreholes on the Colorado Plateau of southeastern Utah
have been examined for evidence of climate change. Because these boreholes penetrate layered
sedimentary rocks with different thermal conductivities, Bullard plots (Temperature versus
integrated thermal resistance) are used to estimate background heat flow and surface temperature
intercepts. Reduced temperatures,...
The southern portion of the Kodiak-Bowie seamonnt chain in the southeastern
Gulf of Alaska presents a unique opportunity to investigate loading on young oceanic
lithosphere. Oceanic lithosphere younger than 25 Ma is loaded both by sediments in a deep
offshore trough and by seamount 100-200 km offshore. Free-air gravity anomaly...
Temperature-depth profiles in borehole CC-I, northwestern Utah, were measured in 1978, 1990, and 1992. Borehole temperatures below 80 m depth are highly reproducible over the 14 year period indicating long term thermal stability. A slowly changing temperature field above 80 m depth has similiar characteristics to synthetic temperature profiles computed...
