Repeat microgravity data from Santa Cruz River, Tucson, Arizona, 2020-2021
Dates
Publication Date
2021-07-21
Time Period
2020-03-02
Time Period
2020-05-13
Time Period
2020-05-27
Time Period
2020-11-06
Time Period
2021-03-05
Citation
Wildermuth, L.M., 2021, Repeat microgravity data from Santa Cruz River, Tucson, Arizona, 2020-2021: U.S. Geological Survey data release, https://doi.org/10.5066/P9K11FAZ.
Summary
Relative-gravity surveys were carried out using a ZLS Burris relative-gravity meter. The effect of solid Earth tides and ocean loading were removed from the data. Instrument drift was removed by evaluating gravity change during repeated measurements at one or more base stations. Absolute-gravity surveys were carried out using a Micro-g LaCoste, Inc. A-10 absolute-gravity meter. Vertical gradients between the different measuring heights of the absolute- and relative-gravity meters were measured using a relative-gravity meter and fully-adjustable tripod, and used to correlate the measurements between the two instruments. Relative-gravity differences and absolute-gravity data were combined using a least-squares network adjustment, as [...]
Summary
Relative-gravity surveys were carried out using a ZLS Burris relative-gravity meter. The effect of solid Earth tides and ocean loading were removed from the data. Instrument drift was removed by evaluating gravity change during repeated measurements at one or more base stations. Absolute-gravity surveys were carried out using a Micro-g LaCoste, Inc. A-10 absolute-gravity meter. Vertical gradients between the different measuring heights of the absolute- and relative-gravity meters were measured using a relative-gravity meter and fully-adjustable tripod, and used to correlate the measurements between the two instruments. Relative-gravity differences and absolute-gravity data were combined using a least-squares network adjustment, as implemented in the software GSadjust (https://doi.org/10.5066/P9YEIOU8). Information about the network adjustment is provided under Data Quality in the metadata.
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Heritage_AdjustedGravity_2020-2021.xml Original FGDC Metadata
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Heritage_AdjustedGravity_2020-2021.csv
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Purpose
Data were collected in cooperation with Tucson Water to evaluate aquifer-storage change along a portion of the Santa Cruz River. The 2020-05-13 survey contains data collected during channel modification that removed a layer of sediment from the River. The 2020-05-27 survey contains data collected immediately following the channel modifications, and reflect changes in gravity (relative to the 2020-03 survey) due mostly to channel excavations in the Santa Cruz River. These surveys only included stations close to the River since the effect of mass removal in the channel decreases with distance from that mass change. Data are not corrected for soil-moisture variation (that is, estimated storage changes include all storage change between the land surface and the aquifer).
