Multi-Sensored Small Diameter Cased Borehole for EEW – Turn an EEW Station Into an Greater Capability Long Term Observatory and Monitoring Solution

Date: 4/24/2019

Time: 06:00 PM

Room: Fifth Avenue

As the requirements and science evolves for improved EEW, a more capable infrastructure would enable greater monitoring capabilities. We propose a deeper grouted casing when appropriately using borehole best practices to ensure improved coupling for lower noise high and low frequency recording. Casing emplacements should be a day operation for installation and a subset could be used for the densification of geodetic arrays with only slight modifications by using the wellhead as a monument supporting the antenna as has been demonstrated on some PBO borehole stations. Stations using a new slimline T120PH and dual sensor Cascadia in a single cased hole will add large dynamic range, resiliency and low noise recording that would enable prompt gravity wave observations along with higher sensitivity for local earthquake recording. Dry cased holes are the standard for long term geophysical observatories and a better investment when all the associated costs of operating EEW observatories are considered while recognizing that these networks are in their infancy in the evolution of hazard monitoring best practices.

Presenting Author: Tim Parker

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