Outline of Session


Solid Earth Sciences(S) / Complex & General(CG) /  **International Session
S-CG15 Detection of microcracks prior to rupture and layered interfaces by the seismoelectronical method

Short title Microcracks and crustal structure
Oral presentation
May 24 PM1 (15:15 - 16:00) 203 Niels Grobbe  / Yukio Fujinawa 
May 24 PM2 (16:15 - 18:00) 203 Yasuhide Hobara  / Qinghua Huang 
Poster presentation
May 24 (Core Time 18:15 - 19:30) Convention Hall
Contact Yukio Fujinawa
Email hjfujinawa@cl.cilas.net
Convener Yukio Fujinawa  / Yasuhide Hobara  / Qinghua Huang  / Niels Grobbe 
Scope The microcrack has been widely investigated in various disciplines including seismology and geotechnical engineering communities. Disastrous natural events such as earthquakes, volcanic eruptions or landslides are considered as ruptures of the Earth's crust consisting of heterogeneous rocks. These ruptures have been known to be preceded by small microcracks in the preparatory stage. They are accompanied by so-called acoustic emission (AE) and seismo- electromagnetic phenomena providing means to investigate the rupture process of earthquake and ground slides, rock bursts in mines, and health check of tunnels. Moreover, seismoelectronics has been developed as new windows to determine physical parameters of the crust and its fluids in the geophysical exploration using active sources. The method has been used for detecting the electrical, hydraulic, and/or mechanical properties by measuring the mechanical energy conversion characteristics into electromagnetic energy at crustal macroscopic interfaces. The research on the seismo-electromagnetic fields had a remarkable progress in the early 1990's. Examples are 1) the seismoelectric conversion generating an independently diffusing electromagnetic field at material contrasts for surveying for oil and gas, 2) the coupling between seismic and electromagnetic phenomena, 3) the ULF band anomalies associated the slow-slip of subducting slab, 4) the combination of both seismic resolution and electromagnetic (fluid) sensitivity, and 5) the possible detection of micro-cracks preceding natural earthquakes. We intend to present state-of-the-art investigations on microcracks in a variety of disciplines, amongst which are new findings using seismoelectric phenomena and other new techniques for understanding of the microcracks preceding crustal ruptures. We hope to contribute in building a more practical short-term prediction method and in developing geophysical prospecting.

Time Presentation No Title Author Presenter Abstract
Oral Presentation   May 24 PM1 (15:15-16:00) 203                              to the top
15:15 - 15:35 Invited
Electromagnetic fields in the solid material neighbouring porous media REN, Hengxin
HUANG, Qinghua
CHEN, Xiaofei
REN, Hengxin English
15:35 - 15:50 SCG15-02 Exclusion of metal contact noise in the experiment of radio wave emission due to rock fracture TAKANO, Tadashi
TAKANO, Tadashi English
Oral Presentation   May 24 PM2 (16:15-18:00) 203                              to the top
16:15 - 16:35 Invited
Medium effect on the characteristics of electromagnetic signals accompanying with seismic waves HUANG, Qinghua
REN, Hengxin
HUANG, Qinghua English
16:35 - 16:50 SCG15-04 Properties of seismo-electric variations induced by microcracks in the nucleation stage of earthquake occurrence FUJINAWA, Yukio
NODA, Yoichi
FUJINAWA, Yukio English
16:50 - 17:05 SCG15-05 The Mechanism of the Pre-seismic Changes of the Tidal Deviation of Groundwater Level in Hualien City, Taiwan LAI, Wenchi
WANG, Shihjung
HSU, Kuochon
LAI, Wenchi English
17:05 - 17:25 Invited
Seismoelectric Interferometry GROBBE, Niels
SLOB, Evert
GROBBE, Niels English
17:25 - 17:40 SCG15-07 Feasibility study of characterizing crustal cracks by EMR in the VLF band using interferometry LIU, Lanbo
HUANG, Qinghua
LIU, Lanbo English
17:40 - 17:55 3-min talk in an oral session (SCG15-P01/SCG15-P02)

Presentation No Title Author Presenter Abstract
Poster Presentation   May 24  Core Time (18:15-19:30) Convention Hall                    to the top
SCG15-P01 Towards Seismoelectric Inversion: Sensitivity Analysis using Resolution Functions GROBBE, Niels
MAAS, Peter
SLOB, Evert
GROBBE, Niels English
SCG15-P02 Application Prospects of SKZ-1 4-component borehole strain meter KONG, Xiangyang
SU, Kaizhi
KONG, Xiangyang English