Monitoring earthquakes with gravity meters

3.04 Gravimetric Methods – Superconducting Gravity Meters

3.04.1 The Superconducting Gravimeter 66 3.04.1.1 Historical 66 3.04.1.1.1 Early years at UCSD 66 3.04.1.1.2 Early commercial model TT instruments (1981–94) 67 3.04.1.1.3 The Compact SG (1994–2002) 68 3.04.1.2 Basic Principles of Operation 69 3.04.1.2.1 Superconducting components 69 3.04.1.2.2 Displacement transducer and feedback system 71 3.04.1.2.3 Temperature control 71 3.04.1.2.4 Tilt compe...

Monitoring Steam-Assisted Gravity Drainage (SAGD) with EIT

Steam-assisted gravity drainage (SAGD) is a technique that has been developed to efficiently extract bitumen from deep reservoirs. We propose using electrical impedance tomography (EIT) for real-time monitoring of SAGD wells to maintain optimal operating conditions. Several electrode configurations along the pipelines and measurement strategies are presented and compared.

Continuous Gravity Measurements for Reservoir Monitoring

In order to improve the accuracy of repeat gravity surveys for reservoir monitoring, it is desirable to perform continuous gravity measurements in addition to the ordinary survey program. We can apply time series analysis to the continuous recording to evaluate the causes of various gravity variations. We have made continuous gravity measurements using a Scintrex CG-3M gravimeter at several geo...

Monitoring of ULF (ultra-low-frequency) Geomagnetic Variations Associated with Earthquakes

ULF (ultra-low-frequency) electromagnetic emission is recently recognized as one of the most promising candidates for short-term earthquake prediction. This paper reviews previous convincing evidence on the presence of ULF emissions before a few large earthquakes. Then, we present our network of ULF monitoring in the Tokyo area by describing our ULF magnetic sensors and we finally present a few...

A Transportable System for Monitoring Ultra Low Frequency Electromagnetic Signals Associated with Earthquakes