An Active/Passive Nodal Survey in Support of Earth Source Heating at Cornell University

Session: Recent Development in Ultra-Dense Seismic Arrays With Nodes and Distributed Acoustic Sensing (DAS)
Type: Oral
Date: 4/30/2020
Time: 04:00 PM
Room: 110 + 140
Description: 

A combined active/passive seismic survey using a vibroseis source and 400 nodal seismic recorders were carried out on and near Cornell University’s Ithaca campus in support of the ongoing Earth Source Heat Project (ESH). These data were collected over a two-week period in September of 2018.The surveys were designed to delineate stratigraphy and structure a potential drill sites on campus. The use of nodes made deployment with student volunteers practical, as well as facilitating several piggy-back experiments addressing site response variations. The vibrator was obtained from the NEES facility at the University of Texas. Here we report on the vibroseis recordings that have been processed to produce 2D seismic reflection images. Although systematic noise from surface waves was found to be a pervasive problem in the nodal recordings, basic stratigraphy in the immediate vicinity of the proposed well sites was imaged and identified with geological formations based on correlations with regional seismic surveys previously collected for gas exploration and available well data. Local structural disruptions in the dominant layer-cake stratigraphy at the target depths for geothermal drilling were found to be few and relatively minor in terms of offset of geological units. These seismic images did not reveal any features that would preclude exploratory drilling. Initial results from the passive site response monitoring illustrates the flexibility of nodal instrumentation for simultaneous active and passive studies.

Presenting Author: Larry D. Brown

Authors