Miscellaneous Microtremor Array Datasets from the Puget Lowland, Washington State

Abstract:
We compile three microtremor array datasets acquired in three campaigns in the Seattle and Tacoma basins, Washington State. These datasets were acquired between 2007 and 2018. Dataset 1 includes seven sites in the western Seattle and Tacoma basins acquired to image shear-wave velocity (Vs) in the upper 1 km that are suitable for analysis with microtremor methods not requiring uniform sensor spacing. Each array in dataset 1 consists of 10 sensors deployed simultaneously in an asymmetric nested triangular pattern, with the largest interstation spacings of roughly 1 km and minimal spacings of about 57 m. Dataset 2 consists of microtremor data at 17 sites located within the city of Seattle. These microtremor data were acquired with four sensors deployed in three sequentially recorded equilateral triangles with interstation spacings of 33.3 m, 100 m, and 300 m, respectively. Dataset 3 consisted of microtremor data at 20 sites in the Tacoma basin simultaneously acquired with 10 sensors in nested equilateral triangular arrays, similar in array size to dataset 2.  

An analysis of these data was presented at the 2021 Annual Meeting of the Seismological Society of America (Stephenson, W.J., Odum, J.K., Leeds, A., 2021, Shallow Shear-Wave Velocity and Crustal Structure in the Seattle and Tacoma Basins from Microtremor Array Analysis, Seismological Research Letters, v. 91, p. 1309). 

Description of dataset:
The datasets for this investigation consist of microtremor array data collected in three regions of the Puget Lowland, Washington State: 1) western Seattle and Tacoma basins (7 sites), 2) Seattle basin and uplift (17 sites), and 3) Tacoma basin (20 sites). These measurements can be used for constraining regional basin depth and community velocity models in the region. Dataset 1 was acquired with Trillium Compact 20 s-100 Hz three-component (3C) sensors deployed in a ten-sensor nested triangular array with non-uniform sensor spacing; inter-sensor distances ranged from ~57 to ~1000 m. Dataset 2 was acquired with four-sensor triangular arrays with Guralp CMG-40T 3C sensors having flat response from 0.033 Hz to 50 Hz; inter-sensor distances ranged from ~19 to ~300 m. Dataset 3 was acquired with Trillium Compact 3C sensors, as used for dataset 1, deployed in a ten-sensor nested triangular array with uniform sensor spacing; inter-sensor distances ranged from ~19 to ~300 m. Datasets 1 and 3 were recorded on RefTek RT-130 data loggers, whereas dataset 2 was recorded on Kinemetrics K2 data loggers. All data are archived as GNU-zipped tar files in binary Seismic Analysis Code (SAC) format. More information regarding these datasets is provided with the additional documentation provided in this data release.
 
Disclaimer:
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