An Efficient and effective stacking method for MT spectrum data; A Validation study using survey data

Negi, Tateyuki; Umeda, Koji; Matsuo, Koichi*; Asamori, Koichi; Yokoi, Koichi*; Ohara, Hidefumi*

Butsuri Tansa, 64(2), p.153 - 165, 2011/04

https://doi.org/10.3124/segj.64.153

The wide band MT method is recognized as an effective method for identifying deep resistivity structures in the crust. In the method, natural variations in the electric and magnetic fields of the earth are acquired over a wide range of frequencies. World wide, thunderstorm activity produces magnetic fields at frequencies above 1Hz. These natural phenomena create strong MT source signals over the entire frequency spectrum. However, magnetic fields at frequencies below 1Hz activate intermittently, because they are caused by the interaction between solar wind and the magnetosphere and therefore, long recording times are required to obtain usable readings. In noisy regions, the signals may be contaminated by DC train signals and other coherent noise, such as occur in western Japan. When magnetic field data are contaminated by such noise, it is difficult to remove or segregate the contaminated data from the usable data. In the paper, we showed the validity of the new weighted stacking method using survey data contaminated by coherent noise.

None

Matsuo, Koichi*; Yokoi, Koichi*; Negi, Tateyuki*; Kasagi, Toshio*; Takahashi, Takeharu*; Teshima, Minoru*

JNC TJ5410 2005-001, 142 Pages, 2005/03

JNC-TJ5410-2005-001.pdf:18.35MB

The present document is to report the result of resistivity monitoring by using MT(Magnetotelluric) method near the site proposed for the Horonobe Underground Research Program at Horonobe-cho, Hokkaido by the Japan Nuclear Cycle Development Institute. The stationary MT observation system, installed near the HDB-1 borehole on November 2002, was moved to a site at the Hokusei-en, 4km west of the first site. This system is monitoring for the depth of underground resistivity. 0bservation data at the Hokusei-en from February 1st 2004 to January 31st 2005 was added in the investigation in 2004 fiscal year. But, data cannot be acquired from July 8th to November 11th of 2004 due to the disconnection trouble of the optical fiber cable for data transfer.The results were as follows

The Survey of the Omagari fault using Audio frequency Magnetotelluric method in Horonobe research project for the Subsurface Environment

Matsuo, Koichi*; Negi, Tateyuki*; Yokoi, Koichi*; Takahashi, Takeharu*; Teshima, Minoru*

JNC TJ5410 2004-002, 188 Pages, 2004/02

JNC-TJ5410-2004-002.pdf:109.99MB

The present document is to report the results of geophysical survey by electromagnetic method around a site proposed for the Horonobe Underground Research Program at Horonobe-cho, Hokkaido by the Japan Nuclear Cycle Development Institute. Remote-reference AMT(Audio-frequency magnetotelluric) method was carried out at 59 stations over 4 km2 in the area of Hokushin in Horonobe-cho. Two dimensional and three dimensional resistivity inversion analysis was carried out and the resistivity structure from the surface to 1,000m below sea level became clear. The resistivity structure was studied by comparing geological structure presumed from existing geological information. Resistivity contour lines extends NNW-SSE trend in plan of resistivity that is coincident with geological structure. The resistivity distribution was good agreement with existing electrical resistivity log data. At 500m below sea level, the resistivity of South-West part from presumed Omagari-fault was ranges from 1 to 3 ohm-m, and that of North-East part is ranges from 3 to 7 ohm-m.

Geophysical survey by electromagnetic method

*; *; Yokoi, Koichi*

JNC TJ1420 2001-036, 177 Pages, 2001/12

JNC-TJ1420-2001-036.pdf:20.9MB

None

Yokoi, Koichi*; Yoneda, Yoshihiro*; Takahara, Hiroyuki*; Moriya, Toshifumi*

PNC TJ1380 96-002, 68 Pages, 1996/03

PNC-TJ1380-96-002.pdf:3.16MB

None

None

Cho, Hisashi*; Yokoi, Koichi*; Noguchi, Yoshifumi*; Morita, Masaya*; Nakamura, Naoaki*; Takahara, Hiroyuki*; Moriya, Toshifumi*

PNC TJ1380 94-001, 1308 Pages, 1994/03

PNC-TJ1380-94-001.pdf:41.64MB

None

The Adaptive techniques for magnetoterullic survey in the area dominating coherent noise, 1; A Technique for the stacking method of the magnetoterullic spectrum data utilizing the property of power spectrum against the noise

Negi, Tateyuki; Umeda, Koji; Matsuo, Koichi*; Asamori, Koichi; Yokoi, Koichi*

no journal, , 

no abstracts in English