The Variation of the Vertical Electric Field at Ground associated with Earthquakes and Severe Weather

Abstract

Atmospheric electric field plays an important role in the global circuit.In addition to the fair-weather electric field, atmospheric electric field also contains turbulent electric fields which caused by blizzards, sandstorms and volcanic eruptions. Therefore, the observation of the vertical electric field on the surface can be used as an alert indicator of natural disasters to reduce damage and loss. In recent studies, atmospheric electric field is important in the coupling model of the lithosphere-atmosphere-ionosphere system. We also hope to verify the relationship between the earthquake precursor and the electric field by measuring the vertical electric field near the earth’s surface.In order to get a preliminary understanding of the vertical electric field and test the performance of the instrument field mill, we set up the instrument outdoors for long-term measurement tests.It can be observed in the measurement results thatthe vertical electric field is closely related to
precipitation.After further analysis,it was found that the electric field has diurnal variation and interesting signals were observed during the Meinong earthquake (2016/02/06). To further explore the relationship between earthquake precursors and electric fields, it is necessary to select a remote fault zone for a long-term measurement. To make the instrument more suitable for this study, the instrument is modified, including a new microprocessor, a wireless transmission system and a stand-alone power system. The upgraded instrument completed five-day outdoor tests twice and the result confirms this instrument can satisfy the requirements of the design goal.

Date of Award	2018
Original language	English
Supervisor	Bing-Chih Chen (Supervisor)