The Angkor complex is mainly constructed in the 9~13 century by Khmer dynasty and was designated as a world cultural heritage by UNESCO in 1992. The Angkor complex represents the entire range of Khmer art and is also famous for large trees growing on the temple wall (Ta Prohm) and various lichens on the stone surfaces. Angkor Wat temple, constructed of sandstone and laterite, is one of the most popular temples in the complex. The French School of Asian Studies (Ecole française d'Extrême-Orient, EFEO) had performed conservation work in early 20 century. However, it was in poor condition after the Cambodian civil war. During the period of 1986 to 1993, Archaeological Survey of India (ASI) contributed to the Angkor Wat’s conservation including reconstruction of the building itself, replacement of blocks, and removal of vegetation. After completion of the cleaning procedures (nearly 200,000 m) by ASI, the original color, gray to yellowish brown, of the Angkor Wat sandstone was restored. However, after two years, cyanobacteria have colonized large portions of the surface of Angkor Wat temple. We categorized surface of the first gallery wall into four types: 1) area covered by cyanobacteria; 2) un-covered area; 3) exfoliated area; and 4) re-covered area after peeling off. We measure the hardness of the first gallery wall by Schmidt rock hammer. Average rebound value of exfoliated area is 3.7 times higher than cyanobacteria covered area. In Un-covered area, it is 3.6 times higher than cyanobacteria covered area. Cyanobacteria are not protecting the wall surface but are accelerating its weathering by reducing surface hardness. However, it is hard to remove clearly and will be easily covered again.
{"title":"Biological weathering on the first gallery wall of Angkor Wat temple, Cambodia","authors":"Wonsuh Song, Tetsuya Waragai, C. Oguchi","doi":"10.4157/ejgeo.11.585","DOIUrl":"https://doi.org/10.4157/ejgeo.11.585","url":null,"abstract":"The Angkor complex is mainly constructed in the 9~13 century by Khmer dynasty and was designated as a world cultural heritage by UNESCO in 1992. The Angkor complex represents the entire range of Khmer art and is also famous for large trees growing on the temple wall (Ta Prohm) and various lichens on the stone surfaces. Angkor Wat temple, constructed of sandstone and laterite, is one of the most popular temples in the complex. The French School of Asian Studies (Ecole française d'Extrême-Orient, EFEO) had performed conservation work in early 20 century. However, it was in poor condition after the Cambodian civil war. During the period of 1986 to 1993, Archaeological Survey of India (ASI) contributed to the Angkor Wat’s conservation including reconstruction of the building itself, replacement of blocks, and removal of vegetation. After completion of the cleaning procedures (nearly 200,000 m) by ASI, the original color, gray to yellowish brown, of the Angkor Wat sandstone was restored. However, after two years, cyanobacteria have colonized large portions of the surface of Angkor Wat temple. We categorized surface of the first gallery wall into four types: 1) area covered by cyanobacteria; 2) un-covered area; 3) exfoliated area; and 4) re-covered area after peeling off. We measure the hardness of the first gallery wall by Schmidt rock hammer. Average rebound value of exfoliated area is 3.7 times higher than cyanobacteria covered area. In Un-covered area, it is 3.6 times higher than cyanobacteria covered area. Cyanobacteria are not protecting the wall surface but are accelerating its weathering by reducing surface hardness. However, it is hard to remove clearly and will be easily covered again.","PeriodicalId":14836,"journal":{"name":"Japan Geoscience Union","volume":"106 1","pages":"585-586"},"PeriodicalIF":0.0,"publicationDate":"2016-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90674279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Umeda, Natsuki Yamauchi, Yasutaka Wada, S. Ueno
In the present paper, the finite-Larmor-radius (gyro-viscous) term [K. V. Roberts and J. B. Taylor, Phys. Rev. Lett. 8, 197–198 (1962)] is evaluated by using a full kinetic Vlasov simulation result of the Kelvin-Helmholtz instability (KHI). The velocity field and the pressure tensor are calculated from the high-resolution data of the velocity distribution functions obtained by the Vlasov simulation, which are used to approximate the Finite-Larmor-Radius (FLR) term according to Roberts and Taylor [Phys. Rev. Lett. 8, 197–198 (1962)]. The direct comparison between the pressure tensor and the FLR term shows an agreement. It is also shown that the anisotropic pressure gradient enhanced the linear growth of the KHI when the inner product between the vorticity of the primary velocity shear layer and the magnetic field is negative, which is consistent with the previous FLR-magnetohydrodynamic simulation result. This result suggests that it is not sufficient for reproducing the kinetic simulation result by fluid simulations to include the FLR term (or the pressure tensor) only in the equation of motion for fluid.
在本文中，有限larmorr -半径(陀螺粘性)项[K。V.罗伯茨和J. B.泰勒，物理学家。通过使用开尔文-亥姆霍兹不稳定性(KHI)的全动力学Vlasov模拟结果来评估[Rev. Lett. 8, 197-198(1962)]。速度场和压力张量是由Vlasov模拟得到的速度分布函数的高分辨率数据计算得到的，根据Roberts和Taylor [Phys]的理论，这些数据用于近似有限拉摩尔半径(FLR)项。Rev. Lett. 8, 197-198(1962)。压力张量与FLR项的直接比较表明两者是一致的。当主速度剪切层涡度与磁场内积为负时，各向异性压力梯度增强了KHI的线性增长，这与先前flr磁流体动力学模拟结果一致。这一结果表明，仅在流体的运动方程中包含FLR项(或压力张量)是不足以通过流体模拟再现动力学模拟结果的。
{"title":"Evaluating gyro-viscosity in the Kelvin-Helmholtz instability by kinetic simulations","authors":"T. Umeda, Natsuki Yamauchi, Yasutaka Wada, S. Ueno","doi":"10.1063/1.4952632","DOIUrl":"https://doi.org/10.1063/1.4952632","url":null,"abstract":"In the present paper, the finite-Larmor-radius (gyro-viscous) term [K. V. Roberts and J. B. Taylor, Phys. Rev. Lett. 8, 197–198 (1962)] is evaluated by using a full kinetic Vlasov simulation result of the Kelvin-Helmholtz instability (KHI). The velocity field and the pressure tensor are calculated from the high-resolution data of the velocity distribution functions obtained by the Vlasov simulation, which are used to approximate the Finite-Larmor-Radius (FLR) term according to Roberts and Taylor [Phys. Rev. Lett. 8, 197–198 (1962)]. The direct comparison between the pressure tensor and the FLR term shows an agreement. It is also shown that the anisotropic pressure gradient enhanced the linear growth of the KHI when the inner product between the vorticity of the primary velocity shear layer and the magnetic field is negative, which is consistent with the previous FLR-magnetohydrodynamic simulation result. This result suggests that it is not sufficient for reproducing the kinetic simulation result by fluid simulations to include the FLR term (or the pressure tensor) only in the equation of motion for fluid.","PeriodicalId":14836,"journal":{"name":"Japan Geoscience Union","volume":"22 1","pages":"9"},"PeriodicalIF":0.0,"publicationDate":"2016-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79498072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-03-10DOI: 10.14866/AJG.2016S.0_100288
H. Hata, C. Narama, K. Fukui
Shirouma-Daisekkei is one of the three largest snow patches in the Japanese Alps. More than 10,000 climbers pass on the snow patch every year. The climbers have suffered accidents of rockfall and rock slip. In August 2005, rock slip at the rock wall of Shakushi-dake causes injured two people. In August 2008, rock slip at upper part of snow patch causes two climbers sacrificed (Kariya et al., 2008). In this study, we carried out field survey during 2014-2015, to clarify the state of rockfall and rock slip, and topographical change around Shirouma-daisekkei. Interval camera showed many rock fragments appeared from inside of snow emerged by declining snow surface in 2014. On the other hand, many rock fragments were produced from rock wall after June 2015. The total number of rock fragments (>30cm) is 570 on the snow patch at the end of September. The distribution of rock fragments is local, and reflected the differences in the local geological feature of this study area.
Shirouma-Daisekkei是日本阿尔卑斯山三大雪区之一。每年有一万多名登山者经过这片雪原。登山者遭遇了落石和滑石的事故。2005年8月，沙库什戴克岩壁发生滑坡，造成2人受伤。2008年8月，雪区上部发生岩石滑移，造成2名登山者死亡(Kariya et al.， 2008)。本研究在2014-2015年期间开展了野外调查，以了解Shirouma-daisekkei周围的岩崩、滑岩状况和地形变化。间隔摄像机显示，2014年，由于雪面下降，雪中出现了许多岩石碎片。另一方面，2015年6月以后岩壁产生了大量岩屑。截至9月底，积雪区岩石碎片(>30cm)总数为570块。岩屑分布具有局部性，反映了研究区局部地质特征的差异性。
{"title":"The distribution of rockfall and topographical change in Shirouma Daisekkei, the Northern Japanese Alps","authors":"H. Hata, C. Narama, K. Fukui","doi":"10.14866/AJG.2016S.0_100288","DOIUrl":"https://doi.org/10.14866/AJG.2016S.0_100288","url":null,"abstract":"Shirouma-Daisekkei is one of the three largest snow patches in the Japanese Alps. More than 10,000 climbers pass on the snow patch every year. The climbers have suffered accidents of rockfall and rock slip. In August 2005, rock slip at the rock wall of Shakushi-dake causes injured two people. In August 2008, rock slip at upper part of snow patch causes two climbers sacrificed (Kariya et al., 2008). In this study, we carried out field survey during 2014-2015, to clarify the state of rockfall and rock slip, and topographical change around Shirouma-daisekkei. Interval camera showed many rock fragments appeared from inside of snow emerged by declining snow surface in 2014. On the other hand, many rock fragments were produced from rock wall after June 2015. The total number of rock fragments (>30cm) is 570 on the snow patch at the end of September. The distribution of rock fragments is local, and reflected the differences in the local geological feature of this study area.","PeriodicalId":14836,"journal":{"name":"Japan Geoscience Union","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87883994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-03-10DOI: 10.14866/AJG.2016S.0_100128
Akiko Yamamura, C. Narama, N. Tomiyama, T. Tadono, T. Yamanokuchi
To clarify the current state of mountain permafrost, we researched the distribution, classification, and movement of rock glaciers as an indicator of mountain permafrost in the Kyrgyz Ala-Too Range using field survey, GIS/RS techniques and aerial photograph interpretation. At the examined site, MAAT is -4.62 and MAGST is -1.47 on rock glacier (3500 m asl.) showing environment of mountain permafrost. The distribution of rock glaciers shows the discontinuous permafrost zones are located above 2800 m a.s.l. on the north part and above 3200 m on the south part of the Kyrgyz Ala-Too Range.
为了明确山地多年冻土的现状，我们采用野外调查、GIS/RS技术和航空照片解译等方法，研究了作为山地多年冻土指示物的岩石冰川的分布、分类和运动。在考察点，岩石冰川(海拔3500 m) MAAT为-4.62,MAGST为-1.47，显示了山地冻土环境。岩石冰川的分布表明，吉尔吉斯阿拉图山脉北部海拔2800 m以上，南部海拔3200 m以上为不连续多年冻土带。
{"title":"Spatial distribution of mountain permafrost in northern Tien Shan, Central Asia","authors":"Akiko Yamamura, C. Narama, N. Tomiyama, T. Tadono, T. Yamanokuchi","doi":"10.14866/AJG.2016S.0_100128","DOIUrl":"https://doi.org/10.14866/AJG.2016S.0_100128","url":null,"abstract":"To clarify the current state of mountain permafrost, we researched the distribution, classification, and movement of rock glaciers as an indicator of mountain permafrost in the Kyrgyz Ala-Too Range using field survey, GIS/RS techniques and aerial photograph interpretation. At the examined site, MAAT is -4.62 and MAGST is -1.47 on rock glacier (3500 m asl.) showing environment of mountain permafrost. The distribution of rock glaciers shows the discontinuous permafrost zones are located above 2800 m a.s.l. on the north part and above 3200 m on the south part of the Kyrgyz Ala-Too Range.","PeriodicalId":14836,"journal":{"name":"Japan Geoscience Union","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85255003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
● These are single, unified geographical areas of international geological significance, and are managed with a holistic concept of protection, education and sustainable development ● UNESCO’s work with geoparks began in 2001. It was in 2004 geoparks countries came together at UNESCO with an appeal to form the Global Geoparks Network (GGN) where national geological heritage initiatives will from a global network of exchange and cooperation ● The UNESCO Global Geopark was ratified by 195 member states in 2015 and gives recognition to geological sites and landscapes which are well maintained and in a holistic manner ● At present there are 161 UNESCO Global Geoparks in 44 countries across the world ● The authorities under this body manage and explore the various global heritage sites and its natural and cultural heritage ● UNESCO also does not imply any restriction on the countries regarding the economic activities being held within the Geoparks ● International Conference on Geoparks is conducted on regular intervals where the criteria, and evaluation of the existing and new geoparks is done
{"title":"UNESCO Global Geoparks","authors":"P. Mckeever","doi":"10.1002/9781119681489","DOIUrl":"https://doi.org/10.1002/9781119681489","url":null,"abstract":"● These are single, unified geographical areas of international geological significance, and are managed with a holistic concept of protection, education and sustainable development ● UNESCO’s work with geoparks began in 2001. It was in 2004 geoparks countries came together at UNESCO with an appeal to form the Global Geoparks Network (GGN) where national geological heritage initiatives will from a global network of exchange and cooperation ● The UNESCO Global Geopark was ratified by 195 member states in 2015 and gives recognition to geological sites and landscapes which are well maintained and in a holistic manner ● At present there are 161 UNESCO Global Geoparks in 44 countries across the world ● The authorities under this body manage and explore the various global heritage sites and its natural and cultural heritage ● UNESCO also does not imply any restriction on the countries regarding the economic activities being held within the Geoparks ● International Conference on Geoparks is conducted on regular intervals where the criteria, and evaluation of the existing and new geoparks is done","PeriodicalId":14836,"journal":{"name":"Japan Geoscience Union","volume":"101 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80743833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-03-10DOI: 10.2208/jscejhe.73.i_253
T. Shimozuma, S. Seto
{"title":"Evaluation of the rain rate estimates of GPM/DPR using ground radar data","authors":"T. Shimozuma, S. Seto","doi":"10.2208/jscejhe.73.i_253","DOIUrl":"https://doi.org/10.2208/jscejhe.73.i_253","url":null,"abstract":"","PeriodicalId":14836,"journal":{"name":"Japan Geoscience Union","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80489824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-03-10DOI: 10.1175/JCLI-D-17-0068.1
Y. Yamada, M. Satoh, M. Sugi, C. Kodama, A. Noda, M. Nakano, T. Nasuno
AbstractWe investigated future changes in tropical cyclone (TC) activity and structure using the outputs of a 14-km mesh climate simulation. A set of 30-year simulations were performed under present-day and warmer climate conditions using a nonhydrostatic icosahedral atmospheric model with explicitly calculated convection. The model projected that the global frequency of TCs is reduced by 22.7%, the ratio of intense TCs is increased by 6.6%, and the precipitation rate within 100 km of the TC center increased by 11.8% under warmer climate conditions. These tendencies are consistent with previous studies using hydrostatic global model with cumulus parameterization.The responses of vertical and horizontal structures to global warming are investigated for TCs with the same intensity categories. For TCs whose minimum sea-level pressure (SLP) reaches less than 980 hPa, the model predicted that tangential wind increases in the outside region of the eyewall. Increases in the tangential wind are related to the ele...
{"title":"Response of tropical cyclone activity and structure to a global warming in a high-resolution global nonhydrostatic model","authors":"Y. Yamada, M. Satoh, M. Sugi, C. Kodama, A. Noda, M. Nakano, T. Nasuno","doi":"10.1175/JCLI-D-17-0068.1","DOIUrl":"https://doi.org/10.1175/JCLI-D-17-0068.1","url":null,"abstract":"AbstractWe investigated future changes in tropical cyclone (TC) activity and structure using the outputs of a 14-km mesh climate simulation. A set of 30-year simulations were performed under present-day and warmer climate conditions using a nonhydrostatic icosahedral atmospheric model with explicitly calculated convection. The model projected that the global frequency of TCs is reduced by 22.7%, the ratio of intense TCs is increased by 6.6%, and the precipitation rate within 100 km of the TC center increased by 11.8% under warmer climate conditions. These tendencies are consistent with previous studies using hydrostatic global model with cumulus parameterization.The responses of vertical and horizontal structures to global warming are investigated for TCs with the same intensity categories. For TCs whose minimum sea-level pressure (SLP) reaches less than 980 hPa, the model predicted that tangential wind increases in the outside region of the eyewall. Increases in the tangential wind are related to the ele...","PeriodicalId":14836,"journal":{"name":"Japan Geoscience Union","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87663495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-12-16DOI: 10.14863/GEOSOCABST.2015.0_183
K. Ohata, H. Naruse, M. Yokokawa
{"title":"Discriminant functions for formative conditions of bedforms in open-channel flows","authors":"K. Ohata, H. Naruse, M. Yokokawa","doi":"10.14863/GEOSOCABST.2015.0_183","DOIUrl":"https://doi.org/10.14863/GEOSOCABST.2015.0_183","url":null,"abstract":"","PeriodicalId":14836,"journal":{"name":"Japan Geoscience Union","volume":"8 1","pages":"183"},"PeriodicalIF":0.0,"publicationDate":"2015-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79336425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-11-20DOI: 10.1002/9781118978719.CH5
K. Sakaguchi, K. Shiokawa, Y. Miyoshi, M. Connors
Isolated proton aurora (IPA) in the subauroral ionosphere is created by energetic proton precipitation through wave-particle interactions with electromagnetic ion cyclotron (EMIC) waves in the conjugate inner magnetosphere. In this study, spatial distribution and occurrence probability of IPAs were statistically investigated as a proxy for regions of EMIC wave occurrence using ground-based imaging data in 2006-2012 at Athabasca, Canada. The seven-year average of the IPA occurrence probability over the total observation interval was estimated to be 0.83% and a factor of five change was found between maximum and minimum years. Local time (between 16 and 06 MLT) distribution shows double peaks at pre-midnight and at dusk. The occurrence probability increases with Kp and the MLT location tends to shift duskward. The statistical distribution of IPA size shows a clear peak at a spatial size of 10,000 km 2 , and latitudinal and longitudinal lengths have peaks at 56 and 340 km, respectively, at the ionospheric altitude. The equatorial projections of IPA source locations and two-dimensional structures are estimated by mag-netic field tracing. These spatial structures are essential to quantitatively estimate the loss rate of energetic particles, contributing to space weather studies.
{"title":"Isolated Proton Auroras and Pc1/EMIC Waves at Subauroral Latitudes","authors":"K. Sakaguchi, K. Shiokawa, Y. Miyoshi, M. Connors","doi":"10.1002/9781118978719.CH5","DOIUrl":"https://doi.org/10.1002/9781118978719.CH5","url":null,"abstract":"Isolated proton aurora (IPA) in the subauroral ionosphere is created by energetic proton precipitation through wave-particle interactions with electromagnetic ion cyclotron (EMIC) waves in the conjugate inner magnetosphere. In this study, spatial distribution and occurrence probability of IPAs were statistically investigated as a proxy for regions of EMIC wave occurrence using ground-based imaging data in 2006-2012 at Athabasca, Canada. The seven-year average of the IPA occurrence probability over the total observation interval was estimated to be 0.83% and a factor of five change was found between maximum and minimum years. Local time (between 16 and 06 MLT) distribution shows double peaks at pre-midnight and at dusk. The occurrence probability increases with Kp and the MLT location tends to shift duskward. The statistical distribution of IPA size shows a clear peak at a spatial size of 10,000 km 2 , and latitudinal and longitudinal lengths have peaks at 56 and 340 km, respectively, at the ionospheric altitude. The equatorial projections of IPA source locations and two-dimensional structures are estimated by mag-netic field tracing. These spatial structures are essential to quantitatively estimate the loss rate of energetic particles, contributing to space weather studies.","PeriodicalId":14836,"journal":{"name":"Japan Geoscience Union","volume":"71 1","pages":"59-70"},"PeriodicalIF":0.0,"publicationDate":"2015-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78748612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-05-27DOI: 10.3997/2352-8265.20140180
K. Okamoto, S. Tsuno
It has been adopted empirically that a growth rate of initial P-waves decreases as the epicentral distances become distant. Using this relationship, epicentral distances are estimated from the growth curve of initial P-waves immediately after the occurrence of earthquake in the current Earthquake Early Warning (EEW) system. However the growth rates are not only the function of epicentral distances but also the function of seismic source function, heterogeneous condition of medium, etc. So the growth rates of different earthquakes are fluctuated each other. This fluctuation decreases the accuracy of the EEW. In this study we reveal that a main cause of the fluctuation is seismic scattering and the fluctuation has locality. Finally we propose a robust procedure to estimate epicentral distances considering the locality.
{"title":"Effect of local heterogeneous conditions on growth curves of P-wave","authors":"K. Okamoto, S. Tsuno","doi":"10.3997/2352-8265.20140180","DOIUrl":"https://doi.org/10.3997/2352-8265.20140180","url":null,"abstract":"It has been adopted empirically that a growth rate of initial P-waves decreases as the epicentral distances become distant. Using this relationship, epicentral distances are estimated from the growth curve of initial P-waves immediately after the occurrence of earthquake in the current Earthquake Early Warning (EEW) system. However the growth rates are not only the function of epicentral distances but also the function of seismic source function, heterogeneous condition of medium, etc. So the growth rates of different earthquakes are fluctuated each other. This fluctuation decreases the accuracy of the EEW. In this study we reveal that a main cause of the fluctuation is seismic scattering and the fluctuation has locality. Finally we propose a robust procedure to estimate epicentral distances considering the locality.","PeriodicalId":14836,"journal":{"name":"Japan Geoscience Union","volume":"58 2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86068636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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