Techniques, analysis, and noise in a Salt Lake Valley 4D gravity experiment

Paul Gettings; David S. Chapman; Rick Allis

doi:10.1190/1.2996303

Techniques, analysis, and noise in a Salt Lake Valley 4D gravity experiment

Geophysics ◽

10.1190/1.2996303 ◽

2008 ◽

Vol 73 (6) ◽

pp. WA71-WA82 ◽

Cited By ~ 19

Author(s):

Paul Gettings ◽

David S. Chapman ◽

Rick Allis

Keyword(s):

Salt Lake ◽

Water Levels ◽

Reference Station ◽

Salt Lake Valley ◽

Wasatch Mountains ◽

Gravity Measurements ◽

Elevation Changes ◽

Induced Changes ◽

Irrigation Effects ◽

East West

Repeated high-precision gravity measurements using an automated gravimeter and analysis of time series of [Formula: see text] samples allowed gravity measurements to be made with an accuracy of [Formula: see text] or better. Nonlinear instrument drift was removed using a new empirical staircase function built from multiple station loops. The new technique was developed between March 1999 and September 2000 in a pilot study conducted in the southern Salt Lake Valley along an east-west profile of eight stations from the Wasatch Mountains to the Jordan River. Gravity changes at eight profile stations were referenced to a set of five stations in the northern Salt Lake Valley, which showed residual signals of [Formula: see text] in amplitude, assuming a reference station near the Great Salt Lake to be stable. Referenced changes showed maximum amplitudes of [Formula: see text] through [Formula: see text] at profile stations, with minima in summer 1999, maxima in winter 1999–2000, and some decrease through summer 2000. Gravity signals were likely a composite of production-induced changes monitored by well-water levels, elevation changes, precipitation-induced vadose-zone changes, and local irrigation effects for which magnitudes were estimated quantitatively.

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Thoughts on Utah Archaeology

American Antiquity ◽

10.2307/275789 ◽

1944 ◽

Vol 9 (3) ◽

pp. 319-328 ◽

Cited By ~ 2

Author(s):

Carling Malouf

Keyword(s):

North America ◽

Salt Lake ◽

Salt Lake City ◽

Maximum Height ◽

The South ◽

Wasatch Mountains ◽

The North ◽

Lake City ◽

Number Of Passes ◽

East West

Utah is nearly bisected north-south by the Wasatch Mountains. Between Ogden and Nephi, Utah, these mountains have undergone extensive folding and faulting and reach a maximum height of 12,000 feet at Mt. Timpanogas. South of Nephi this range branches into three great fingers with narrow valleys between. Flanking the Wasatch, east of Salt Lake City, are the lofty Uintah Mountains. These, unlike other ranges in North America, have an east-west axis forming a barrier between Pueblo-dominated lands to the south and the territory of nomads living in the Wyoming Basin to the north. Little evidence of Pueblo occupation has been observed in southeast Wyoming, though there are a number of passes through which occasional hunting parties from the plateaus to the south may have ventured north into the plains of southern Wyoming. This, of course, could only have occurred in the summer, as the area is free from snow for only three or four months of the year.

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Orographic Influences on a Great Salt Lake–Effect Snowstorm

Monthly Weather Review ◽

10.1175/mwr-d-12-00328.1 ◽

2013 ◽

Vol 141 (7) ◽

pp. 2432-2450 ◽

Cited By ~ 40

Author(s):

Trevor I. Alcott ◽

W. James Steenburgh

Keyword(s):

Snow Water Equivalent ◽

Salt Lake ◽

Great Salt Lake ◽

Salt Lake Valley ◽

Wasatch Mountains ◽

Lake Effect ◽

Thermally Driven ◽

Precipitation Band ◽

Northern Utah ◽

Snow Water

Abstract Although several mountain ranges surround the Great Salt Lake (GSL) of northern Utah, the extent to which orography modifies GSL-effect precipitation remains largely unknown. Here the authors use observational and numerical modeling approaches to examine the influence of orography on the GSL-effect snowstorm of 27 October 2010, which generated 6–10 mm of precipitation (snow-water equivalent) in the Salt Lake Valley and up to 30 cm of snow in the Wasatch Mountains. The authors find that the primary orographic influences on the event are 1) foehnlike flow over the upstream orography that warms and dries the incipient low-level air mass and reduces precipitation coverage and intensity; 2) orographically forced convergence that extends downstream from the upstream orography, is enhanced by blocking windward of the Promontory Mountains, and affects the structure and evolution of the lake-effect precipitation band; and 3) blocking by the Wasatch and Oquirrh Mountains, which funnels the flow into the Salt Lake Valley, reinforces the thermally driven convergence generated by the GSL, and strongly enhances precipitation. The latter represents a synergistic interaction between lake and downstream orographic processes that is crucial for precipitation development, with a dramatic decrease in precipitation intensity and coverage evident in simulations in which either the lake or the orography are removed. These results help elucidate the spectrum of lake–orographic processes that contribute to lake-effect events and may be broadly applicable to other regions where lake effect precipitation occurs in proximity to complex terrain.

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Thirty years of precise gravity measurements at Mt. Vesuvius: an approach to detect underground mass movements

Annals of Geophysics ◽

10.4401/ag-6442 ◽

2013 ◽

Vol 56 (4) ◽

Author(s):

Giovanna Berrino ◽

Vincenzo d’Errico ◽

Giuseppe Ricciardi

Keyword(s):

Ground Deformation ◽

Reference Station ◽

Absolute Gravity ◽

Volcanic Area ◽

Gravity Station ◽

Gravity Changes ◽

Gravity Measurements ◽

Elevation Changes ◽

Gravity Network

<p>Since 1982, high precision gravity measurements have been routinely carried out on Mt. Vesuvius. The gravity network consists of selected sites most of them coinciding with, or very close to, leveling benchmarks to remove the effect of the elevation changes from gravity variations. The reference station is located in Napoli, outside the volcanic area. Since 1986, absolute gravity measurements have been periodically made on a station on Mt. Vesuvius, close to a permanent gravity station established in 1987, and at the reference in Napoli. The results of the gravity measurements since 1982 are presented and discussed. Moderate gravity changes on short-time were generally observed. On long-term significant gravity changes occurred and the overall fields displayed well defined patterns. Several periods of evolution may be recognized. Gravity changes revealed by the relative surveys have been confirmed by repeated absolute measurements, which also confirmed the long-term stability of the reference site. The gravity changes over the recognized periods appear correlated with the seismic crises and with changes of the tidal parameters obtained by continuous measurements. The absence of significant ground deformation implies masses redistribution, essentially density changes without significant volume changes, such as fluids migration at the depth of the seismic foci, i.e. at a few kilometers. The fluid migration may occur through pre-existing geological structures, as also suggested by hydrological studies, and/or through new fractures generated by seismic activity. This interpretation is supported by the analyses of the spatial gravity changes overlapping the most significant and recent seismic crises.</p>

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Potential effects of ozone, climate, and spruce budworm on Douglas-fir growth in the Wasatch Mountains

Canadian Journal of Forest Research ◽

10.1139/x02-211 ◽

2003 ◽

Vol 33 (5) ◽

pp. 910-921 ◽

Cited By ~ 5

Author(s):

David J Wager ◽

F A Baker

Keyword(s):

Fungal Pathogens ◽

Salt Lake ◽

Negative Relationship ◽

Douglas Fir ◽

Spring Precipitation ◽

Salt Lake Valley ◽

Ozone Concentrations ◽

Wasatch Mountains ◽

Ozone Injury ◽

Bear River

This study assessed the potential for ozone injury to vegetation in the central Wasatch Mountains of Utah by determining if Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) experienced reduced growth since the onset of high ozone concentrations. Dendrochronological techniques were used to model Douglas-fir growth in six central Wasatch Mountain stands, where ozone concentrations suggest the possibility of injury to vegetation, and in four Bear River stands, where ozone concentrations are lower than injury thresholds. Previous-year growth, temperature, and Palmer's Z index variables explained 5370% of the variance in annual growth. Reduced Douglas-fir growth, not explained by the model or insect and disease records, occurred after 1970 in the central Wasatch Mountains but not in the Bear River Mountains. Douglas-fir growth in the central Wasatch Mountains was slightly negatively correlated with the previous-year ozone concentrations in nearby Salt Lake valley. Between 1962 and 1973, a fluctuating budworm population due to varying spring precipitation was suggested to have replaced precipitation as the factor limiting tree growth, causing an anomalous negative relationship between precipitation and Douglas-fir growth. Because of a suite of possible factors (e.g., undetected climatic variables, fungal pathogens, competitive interactions) influencing Douglas-fir growth, ozone may be one factor in a larger stressor complex reducing growth.

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