Source mechanism of the Alaskan earthquake of 1964 from amplitudes of free oscillations and surface waves — comments     

Hiroo Kanamori 《Physics of the Earth and Planetary Interiors》1973,7(2):222-224

Recently Ben-Menahem et al. (1972) (hereafter abbreviated to B.R.I.) proposed, on the basis of long-period surface-wave and free-oscillation data, a steeply dipping fault model for the Alaskan earthquake of 1964. This result differs from that obtained by Kanamori (1970) (hereafter abbreviated to K.70) who also used long-period Love and Rayleigh waves, but preferred a low-angle fault model. I would like to make several comments on this difference.  相似文献   

Resistivity mapping using the VLF-MT method around surface fault ruptures of the 1995 Hyogo-ken Nanbu earthquake, Japan   总被引：1，自引：0，他引：1  

Satoru Yamaguchi  Takahisa Murakami  Hiroo Inokuchi 《Island Arc》2001,10(3-4):296-305

Abstract Distinctive fault ruptures, the Nojima Fault and Ogura Fault, appeared along the northwestern coast of Awaji Island at the time of the 1995 Hyogo-ken Nanbu earthquake (Kobe earthquake). In order to delineate the shallow resistivity structures around the faults just after they formed, Very Low Frequency Magnetotelluric (VLF-MT) surveys were made at five sites along the Nojima Fault and at one site along the Ogura Fault. Fourteen transects were made at the one site on the Ogura Fault, and another transect covers the area between the two faults. Changes in apparent resistivity or phase, or both, commonly occur when crossing the surface location of one of the faults, except for the northern transects at OGR-0 on the Ogura Fault. Apparent resistivity values of less than 100 Ωm were observed for Tertiary and Quaternary sediments and values larger than 200 Ωm for granitic rocks. The resistivity structures are related to the morphological characteristics of the fault ruptures. Remarkably conductive zones (less than 10 Ωm in apparent resistivity and 30–40 m in width) were found where the surface displacement is distinct and prominent along a single fault plane. If remarkably conductive zones were formed at the time of the 1995 Hyogo-ken Nanbu earthquake, the results provide a good constraint on the dimensions of a conductive zone near the surface that was made by one earthquake. Alternatively, if characteristic resistivity structures existed prior to the earthquake, the conductive zone was probably formed by some tens of earthquakes in relatively modern times. In this case, this phenomenon is inferred to be a concentration of fracturing in a narrow zone and is associated with the formation of clay minerals, which enhance rock conductivity.  相似文献   

Velocity dispersion due to anelasticity; implications for seismology and mantle composition   总被引：13，自引：0，他引：13  

Hsi-Ping LiU  Don L. Anderson  Hiroo Kanamori 《Geophysical Journal International》1976,47(1):41-58

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Paleomagnetic evidence for post-Cretaceous internal deformation of the Chuan Dian Fragment in the Yangtze block: a consequence of indentation of India into Asia   总被引：3，自引：0，他引：3  

Shinya Yoshioka  Yu Yan Liu  Ken Sato  Hiroo Inokuchi  Li Su  Haider Zaman  Yo-ichiro Otofuji   《Tectonophysics》2003,376(1-2):61-74

Paleomagnetic samples of Paleocene–Eocene red sandstones were collected at 36 sites from the Jiangdihe-4 and Zhaojiadian formations around the Yongren (26.1°N, 101.7°E) and Dayao areas (25.7°N, 101.3°E). These areas are located in the Chuxiong basin of the Chuan Dian Fragment, southwestern part of the Yangtze block. After stepwise thermal demagnetization, a high-temperature component with unblocking temperature of about 680 °C is isolated from 26 sites. The primary nature of this magnetization is ascertained through positive fold and reversal tests at 95% confidence level. The tilt-corrected mean paleomagnetic directions for the Yongren and Dayao areas are D=17.2°, I=26.6° with α₉₅=5.8° and D=16.5°, I=31.1° with α₉₅=4.8, respectively. Easterly deflected declinations from this study are consistent with those reported from other areas of the Chuxiong basin, indicating its wide presence in the Cretaceous–Eocene formations of the said basin. Comparison with declination values expected from the Cretaceous–Eocene APWP of Eurasia indicates that the magnitude of clockwise rotation systematically increases toward the southeast within the Chuxiong basin as well as in the Chuan Dian Fragment. This trend of the differential tectonic rotation in the Chuan Dian Fragment is consistent with curvature of the Xianshuihe–Xiojiang fault system. Deformation of the Chuxiong basin can fairly be associated with the formation of eastward bulge in the southern part of the Chuan Dian fragment. During southward displacement, the Chuan Dian Fragment was probably subjected to tectonic stresses as a result interaction with the Yangtze and Indochina blocks, which resulted into east–west extension and north–south shortening.  相似文献   

Changes in the hypsometric curve through mountain building resulting from concurrent tectonics and denudation   总被引：1，自引：0，他引：1  

Hiroo Ohmori 《Geomorphology》1993,8(4)

The stages of geomorphic development of mountains have sometimes been explained based on Strahler's diagram of hypsometric curves. Although the Japanese mountains are young, they do not follow his diagram. Hypsometric curves, simulated using empirical laws deduced from the Japanese mountains, indicate that mountain building resulting from concurrent tectonics and denudation does not produce convex curves but concave and/or s-shaped curves. The hypsometric curve of a mountain changes from a concave curve to an s-shaped curve in accordance with the increase in mountain altitude. The succession of the hypsometric curve during concurrent tectonics and denudation is the reverse of Strahler's diagram. The hypsometric integral increases with the advance in stage which is evaluated based on the change in mountain altitude. It has a relatively good correlation with the stage. However, the sequence of change in the hypsometric integral is different according to the extent of the terrain examined, whether the terrain is restricted to the interior of a mountain or pertains to the whole mountain, and whether it includes newly emerged land. The stage should be evaluated based on the course of change in the integral characteristics for the extent of the mountain examined.  相似文献   

Counter-clockwise rotation of the eastern part of the Mongolia block: Early Cretaceous palaeomagnetic results from Bikin, Far Eastern Russia     

Yo-ichiro Otofuji  Daisuke Miura  Koichi Takaba  Kazuhiro Takemoto  Kazutoshi Narumoto  Haider Zaman  Hiroo Inokuchi  Ruslan G. Kulinich  Petr S. Zimin  Vladimir G. Sakhno 《Geophysical Journal International》2006,164(1):15-24

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辐射能量和地震断层物理机制     

McGarr  Abercrombie  Kanamori  杨勇 《国际地震动态》2007,(3):43-45

美国地球物理联合会(American Geo-physical Union)最近在美国缅因州波特兰举行了AGU Chapman会议。在接近Two Lights断层区域和Fort Foster脆性区域,现场考察了大西洋沿岸岩石暗礁。现场考察的负责人Dr.Mark Swanson和他的学生在过去20年来详细地研究了该区域,与会人员考察了3  相似文献   

Researches on the stability of porphyra-334 solution and its influence factors     

ZHANGZhaohui GAOXin YuriTashiro ShingoMatsukawa HirooOgawa 《中国海洋大学学报(英文版)》2004,3(2):166-170

1　Introduction　Ultravioletradiationisahighlyactivecomponentofsolarspectrum .Ultravioletradiationhasdetrimentaleffectsonlivingthingsexposedtosunlight ,includingthedestructionofDNA ,proteinsandothermolecules(Harm ,1980 ) ,inhibitionofphotosynthesisandgrow…  相似文献   

Calcium-alkalinity relationship in the North Pacific   总被引：3，自引：0，他引：3  

Satoru Kanamori  Hisashi Ikegami 《Journal of Oceanography》1982,38(2):57-62

The dissolution of calcium carbonate in deep ocean water causes variation in calcium concentration (Ca) and alkalinity (TA) in the ratio of one to two. The decomposition of organic matter generates nitric acid, phosphoric acid and sulfuric acid. A proton flux which is derived from this process also changes alkalinity. Using the variation in nitrate concentration (NO₃) as an index of the proton flux, the relationship betweenCa,TA andNO₃ is expressed asCa=0.5TA+0.63NO₃ The values of Ca obtained from direct measurements in the North Pacific are in good agreement with the values estimated from this equation.  相似文献   

Primary productivity in the fast ice area near syowa station,Antarctica, during spring and summer 1983/84     

Hiroo Satoh  Kentaro Watanabe 《Journal of Oceanography》1988,44(6):287-292

In situ measurements of the primary productivity of ice algae and phytoplankton were carried out in the fast ice area near Syowa Station (69°00S, 39°35E) during the austral spring and summer of 1983/84. Standing stock of ice algae reached a maximum of 45.1 mg chla m^–2 in late October. Phytoplankton standing stock attained a value of 3.57 mg chla m^–2 in mid-January. Primary production of ice algae in late October (7.64 mgC m^–2 hr^–1) was 14 times greater than that in mid-January (0.54 mgC m^–2 hr^–1). Production in the water column in mid-January (3.46 mgC m^–2 hr^–1) was 50 times greater than that in late October (0.07 mgC m^–2 hr^–1). These results indicate a substantial production by ice algae in the spring and by phytoplankton in the summer period.  相似文献