result 211 件
| FullText URL | esr_029_cover_j.pdf |
|---|---|
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2023-03-31 |
| Volume | volume29 |
| Issue | issue1 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | © 2023 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| FullText URL | esr_029_colophon.pdf |
|---|---|
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2023-03-31 |
| Volume | volume29 |
| Issue | issue1 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | © 2023 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| Title Alternative | ERRATA: FDM simulation of long-period ground motions around Oita Prefecture, Japan, using a land-ocean unified 3D structure model |
|---|---|
| FullText URL | esr_029_065_066.pdf |
| Author | OKUNAKA, Tatsuya| KOMATSU, Masanao| TAKENAKA, Hiroshi| YOSHIMI, Masayuki| NAKAMURA, Takeshi| OKAMOTO, Taro| |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2023-03-31 |
| Volume | volume29 |
| Issue | issue1 |
| Start Page | 65 |
| End Page | 66 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | © 2023 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| JaLCDOI | 10.18926/ESR/65481 |
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| Title Alternative | Onset time and location of the main rupture of the 2018 Hokkaido Eastern Iburi, Japan, earthquake |
| FullText URL | esr_029_049_063.pdf |
| Author | KOWARI, Hirofumi| KOMATSU, Masanao| TAKENAKA, Hiroshi| |
| Abstract | The rupture process at the beginning stage of the 2018 Hokkaido Eastern Iburi, Japan, earthquake (MJ 6.7) is investigated by analyzing P-wave records from local strong-motion stations. The records show about 3 s of small amplitude arrival (so-called "initial rupture phase") followed by the onset of the main energy release ("main rupture phase"). In this paper we address the issue: where the seismic energy release corresponding to the main rupture phase started at the primary stage of the main rupture, by locating the main rupture onset position. For this aim we applied the 2D and the 3D search methods to estimate the relative location of the onset of the main rupture with respect to the hypocenter, and the time difference between them. The 2D method assumes a plausible initial fault plane and locates the main rupture onset position on the initial fault plane, while the 3D method does not require such assumed fault planes. In the 2D method we employed each of the nodal planes of the first-motion focal mechanism as the initial rupture plane. The 3D method was able to give a better solution than the 2D one. It suggests that the main rupture initiation point might not be on the same fault plane as the hypocenter is. The solution shows that the main rupture onset point is 5.8 km southward and 2.5 km upward from the hypocenter, with the rupture time of 3.3 s from the origin time. It is consistent with the previous studies on the relationship between the magnitude and the initial rupture duration. |
| Keywords | 2018 Hokkaido Eastern Iburi earthquake fault plane initial rupture strong motion |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2023-03-31 |
| Volume | volume29 |
| Issue | issue1 |
| Start Page | 49 |
| End Page | 63 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | © 2023 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| JaLCDOI | 10.18926/ESR/65480 |
|---|---|
| Title Alternative | Summary of our activities toward development of the ESD interdisciplinary study plans on climate and cultural understanding education with attention to the seasonal cycle and “seasonal feeling” around Japan and Europe |
| FullText URL | esr_029_029_048_rev.pdf |
| Author | KATO, Kuranoshin| KATO, Haruko| AKAGI, Rikako| |
| Abstract | We have continued the interdisciplinary integration of the knowledge on climate and music and have developed the crosscutting study plans on the climate and cultural understanding education. A part of these results had been summarized in a Japanese book titled “Climate and music (Cultural understanding and ESD spreading from the “Doors of Song”)” (Kato and Kato 2019), building mainly our papers written in Japanese. This article will re-integrate our above study results, mainly for the climate and songs/traditional seasonal events around Germany, Northern Europe and Japan, with special attention to (A) asymmetric seasonal progression from autumn to next spring around Japan, (B) winter climate around Germany in association with the seasonal feeling on the traditional events “Fasnacht” for driving winter away and (C) climate around Northern Europe in association with the seasonal feeling on the summer solstice festival “Juhannus” with comparison to the summer climate around Japan. |
| Keywords | climate and music interdisciplinary climate and cultural understanding education seasonal cycle around Japan and Europe seasonal feeling ESD comparative climatology |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2023-03-31 |
| Volume | volume29 |
| Issue | issue1 |
| Start Page | 29 |
| End Page | 48 |
| ISSN | 1340-7414 |
| language | English |
| Copyright Holders | © 2023 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| JaLCDOI | 10.18926/ESR/65479 |
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| Title Alternative | Geology of the Paleogene to Neogene successions and gentle upwarping of the Kibi Plateau Surface, surrounding area of Kibichuou Town, Okayama Prefecture, Southwest Japan |
| FullText URL | esr_029_001_027.pdf |
| Author | TANAKA, Hajime| SUZUKI, Shigeyuki| |
| Abstract | The Paleogene to Neogene successions which are composed of the Paleogene Kayo Formation, the late Oligocene to earliest Miocene Yagane Formation and the middle Miocene Ukan Formation are sporadically distributed in the Kibi Plateau region, surrounding area of Kibichuou Town, Okayama Prefecture, Southwest Japan. The gravel of the Kayo Formation occupied paleo-valley of Pre-Paleogene basement. The Yagane and Ukan formations unconformably overlay Pre-Paleogene rocks and occupy the gentle valley on the Kibi Surface as valley fill deposits. The fluvial of the Kayo Formation is mainly composed of conglomerate with minor amount of sandstone and mudstone. The fluvial Yagane Formation is mainly composed of conglomerate and associated with sandstone, mudstone and coal beds. The marine Ukan Formation is subdivided into 3 members, the Yamagata Muddy sandstone Member (YMM), the Shimoyokomi Sandstone Member (SSM) and the Tsuneyama Mudstone Member (TMM) in ascending order. The YMM is characterized by the bio-disturbed very poorly sorted muddy sandstone with frequent burrows, which indicate tidal flat deposits. The SSM is mainly composed of parallel bedded well-sorted sandstone with occasional burrows, which suggest near shore deposits. The TMM is composed of homogeneous clay rich mudstone, which implies off shore deposits. The boundary between the SSM and TMM (the contact of the sandstone and mudstone) is distinctive and correlative throughout the study area. The boundary is considered to be formed under similar water depth. The variations of the boundary height indicate a later ground movement. From the north to the south in about 25km distance, the height of the boundary changes 260m (in Ukan), 300m (in Takeshou), 360m (in Kibikogentoshi) and 260m (in Nichiouji). It indicates that a very gentle upwarping of the Kibi Plateau Surface was formed after the deposition of the Miocene. |
| Keywords | Kibi Plateau Surface Upwarping Miocene Ukan Formation |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2023-03-31 |
| Volume | volume29 |
| Issue | issue1 |
| Start Page | 1 |
| End Page | 27 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | © 2023 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| FullText URL | esr_029_titlepage.pdf |
|---|---|
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2023-03-31 |
| Volume | volume29 |
| Issue | issue1 |
| ISSN | 1340-7414 |
| language | English |
| Copyright Holders | © 2023 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| FullText URL | esr_029_cover.pdf |
|---|---|
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2023-03-31 |
| Volume | volume29 |
| Issue | issue1 |
| ISSN | 1340-7414 |
| language | English |
| Copyright Holders | © 2023 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| FullText URL | esr_028_cover_j.pdf |
|---|---|
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2022-03-31 |
| Volume | volume28 |
| Issue | issue1 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | © 2022 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| FullText URL | esr_028_colophon.pdf |
|---|---|
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2022-03-31 |
| Volume | volume28 |
| Issue | issue1 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | © 2022 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| JaLCDOI | 10.18926/ESR/63515 |
|---|---|
| Title Alternative | FDM simulation of long-period ground motions around Oita Prefecture, Japan, using a land-ocean unified 3D structure model |
| FullText URL | esr_028_027_103.pdf |
| Author | Okunaka, Tatsuya | Komatsu, Masanao| Takenaka, Hiroshi| Yoshimi, Masayuki| Nakamura, Takeshi| Okamoto, Taro| |
| Abstract | Oita prefecture is located in northeastern part of Kyushu Island which is characterized by active subduction of the Philippine Sea plate (PHS) beneath the Eurasian plate and several active volcanoes along with the volcanic front. Oita area has frequently been damaged by large earthquakes and tsunamis since ancient times. From the point of view of disaster prevention, it is important to investigate the feasibility of strong ground motion prediction using realistic structural models. In this paper we use a land-ocean unified 3D (three-dimensional) structure model around Oita prefecture, which includes land and sea-floor topography and a seawater layer as well as subsurface structures of the arc side and the PHS slab to conduct the FDM (finite-difference method) simulations of strong ground motion in land and ocean areas for the 2015 Southern Oita, Japan, earthquake (MJMA5.7) whose hypocenter is located in the PHS slab. The simulated long-period (2–20 s) ground motions reproducing observed records demonstrate substantial contributions of thick low-velocity sediment layers in and around Beppu Bay and Oita basin to development of the motions. We also examine the topographic effects on the seismic motion by analyzing the simulation results to show the strong enhancement of the later phases. |
| Keywords | strong motion Oita the 2015 Southern Oita earthquake long-period ground motion simulation finite-difference method topography |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2022-03-31 |
| Volume | volume28 |
| Issue | issue1 |
| Start Page | 27 |
| End Page | 103 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | © 2022 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| JaLCDOI | 10.18926/ESR/63514 |
|---|---|
| Title Alternative | Depositional history of the Paleogene to Neogene valley fill deposits and topographic change in the Kibi Plateau region, Okayama City, Southwest Japan |
| FullText URL | esr_028_001_025.pdf |
| Author | Tanaka, Hajime| Suzuki, Shigeyuki| |
| Keywords | Kibi Plateau Surface Paleogene Kibi Group Miocene Bihoku Group |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2022-03-31 |
| Volume | volume28 |
| Issue | issue1 |
| Start Page | 1 |
| End Page | 25 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | © 2022 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| FullText URL | esr_028_titlepage.pdf |
|---|---|
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2022-03-31 |
| Volume | volume28 |
| Issue | issue1 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | © 2022 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| FullText URL | esr_028_cover.pdf |
|---|---|
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2022-03-31 |
| Volume | volume28 |
| Issue | issue1 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | © 2022 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| FullText URL | esr_027_cover_j.pdf |
|---|---|
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2021-03-31 |
| Volume | volume27 |
| Issue | issue1 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | © 2021 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| FullText URL | esr_027_colophon.pdf |
|---|---|
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2021-03-31 |
| Volume | volume27 |
| Issue | issue1 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | © 2021 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| JaLCDOI | 10.18926/ESR/61959 |
|---|---|
| Title Alternative | Estimation of displacement waveforms by baseline correction of near-fault acceleration records of the 2016 Kumamoto earthquake with median filter |
| FullText URL | esr_027_039_050.pdf |
| Author | Watanabe, Tomotsugu| Komatsu, Masanao| Takenaka, Hiroshi| |
| Abstract | The 2016 Kumamoto earthquake sequence occurred on April 14 (MJMA 6.5) and April 16 (MJMA 7.3). Seismic intensity of 7 on the Japan Meteorological Agency (JMA) scale was observed in Mashiki Town, Kumamoto Prefecture for the both events and in Nishihara Village, Kumamoto Prefecture for the April-16 event. We estimate the displacement waveforms from these acceleration records. Since the acceleration seismograms include the long-period noise due to tilting of the ground and instrumental effects, the baseline corrections are required to derive the accurate velocity and displacement waveforms. We apply a median filter to the velocity waveforms to identify the linear trends on them due to the steplike noise on the acceleration records, and determine the time at which baseline shifts take place and the step value of each shift for the baseline correction through trial and error. Our baseline correction can successfully reconstruct the velocity and displacement waveforms from the acceleration records. The displacement waveforms show the static components consistent with the geodetic data. |
| Keywords | 2016 Kumamoto earthquake baseline correction median filter displacement |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2021-03-31 |
| Volume | volume27 |
| Issue | issue1 |
| Start Page | 39 |
| End Page | 50 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | © 2021 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| NAID | 120007037380 |
| JaLCDOI | 10.18926/ESR/61956 |
|---|---|
| Title Alternative | Synthetic nearfield seismograms at a subsurface position in a horizontally layered half-space |
| FullText URL | esr_027_029_038.pdf |
| Author | Takenaka, Hiroshi| Watanabe, Tomotsugu| |
| Abstract | We extend the computational code of Takenaka and Sasatani (2000) for synthetic nearfield seismograms for horizontally layered elastic media, based on the reflection/transmission matrices and the discrete wavenumber summation method, to calculate seismic motion and its spatial derivatives at a subsurface position in the attenuative media. In this paper we describe the theory of this extension and show some numerical examples to verify the extended code. |
| Keywords | synthetic seismogram reflectivity method layered half-space |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2021-03-31 |
| Volume | volume27 |
| Issue | issue1 |
| Start Page | 29 |
| End Page | 38 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | © 2021 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| NAID | 120007037377 |
| JaLCDOI | 10.18926/ESR/61955 |
|---|---|
| Title Alternative | The Kibi Plateau Surface ― relationship with the Paleogene and Miocene deposits in middle western part of Okayama Prefecture, Japan ― |
| FullText URL | esr_027_019_027.pdf |
| Author | Tanaka, Hajime | Suzuki, Shigeyuki| |
| Abstract | The Kibi Plateau Surface is associated with the Paleogene gravel river bed deposits of the Kibi Group and the Miocene marine deposits of the Katsuta Group and the Bihoku Group. These Paleogene and Miocene units are valley fill deposits. The Kibi Group is composed of formations which is deposited by more than 7 different depositional events during earliest to latest Paleogene Period. Repeated cycles of “erosion - formation of new valley system - deposition and fill up the valley” created the low relief topographic surface. The deposition of the Miocene deposits might complete the Kibi Plateau Surface. Detailed field works have done in middle western part of Okayama Prefecture. The Kibi Plateau Surface in study area is gently dipping from NW (about 600m high) to SE (about 100m high). The distributions of the Paleogene and Miocene deposits fit the surface. At the southern margin of the Kibi Plateau, the surface is a little inclined (from 400m high to 100m high) where the bottom of paleo-valleys of the Paleogene deposits are subparallel to the surface. It suggests that the gentle tilting of the Kibi Plateau is caused by an up-warping. |
| Keywords | Kibi Plateau Surface Paleogene Neogene Miocene |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2021-03-31 |
| Volume | volume27 |
| Issue | issue1 |
| Start Page | 19 |
| End Page | 27 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | © 2021 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| NAID | 120007037376 |
| JaLCDOI | 10.18926/ESR/61954 |
|---|---|
| Title Alternative | For development of an ESD-based teacher training program on climate change : overlooking geo-phenomena on various timescales |
| FullText URL | esr_027_001_017.pdf |
| Author | Kato, Yuji| Kato, Kuranoshin| |
| Abstract | Since the recent climate change is an important topic in the context of SDGs (Sustainable Development Goals) and ESD (Education for Sustainable Development), teacher training course should produce educators with sufficient geo-literacy. In order to meet this requirement, the authors have designed a study plan that facilitates students’ better understanding of current climate change issues, which will be offered in a lecture at university by two speakers who have different specialties, paleoenvironmental science and meteorology. Summary of the lecture is as follows. At first, from the branch of paleoenvironmental science, a major cooling event at the Eocene/Oligocene boundary and the glacial-interglacial cycles in the Quaternary will be explained. We will then instruct the participants to compare these climatic events with recent global warming, in order to remind them of the extraordinary higher speed of the recent climate change than climatic events in the geological past. Followed by these global topics, climatological features in East Asia including Japan (e.g. regional/seasonal difference in climate and year-to-year variations) will be demonstrated in order to relate local issues to global ones. By these efforts, the lecture aims to cultivate students’ ability to grasp geophenomena from various aspects and understand the true nature of problems, which may contribute producing educators who can execute ESD programs. |
| Keywords | time scales geologic events paleoenvironmental science meteorology and climatology global warming ESD SDGs |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2021-03-31 |
| Volume | volume27 |
| Issue | issue1 |
| Start Page | 1 |
| End Page | 17 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | © 2021 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved |
| File Version | publisher |
| NAID | 120007037387 |
