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"Takano Family Record” is investigated to reveal seismic activity in southern Miyagi Prefecture in the 18th century. "Takano Family Record" is a diary recorded by the successive heads of the Takano family between 1696 and 1782 and is included in a published collection of historical documents on earthquakes in Japan. About 150 days of felt records are newly found from our investigation of microfilmed original records kept in the library of the Graduate School of Arts and Letters, Tohoku University. Comparison between the number of felt earthquakes recorded in the "Takano Family Records" that observed by modern observations shows that the author of the "Takano Family Records" recorded earthquakes of JMA seismic intensity 2 or higher, as well as some earthquakes of intensity 1. "Takano Family Records" also contains descriptions of earthquake damage. Location and magnitude of the May 4, 1767 and October 22, 1767 earthquakes are reexamined from distribution of damage and felt records as well as the number of aftershocks., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

＜報告＞

史料にみられる液状化現象の詳細な分析により，将来の液状化の発生について評価することができる。1854年伊賀上野地震は山城（現在の京都府南部）に被害を及ぼしたが，伏見（現在の京都市伏見区）で局所的に液状化が発生しており，備前岡山藩の記録に泥や砂の噴出や蔵の倒壊が記述されている。史料や地図の詳細な検討により，この液状化の発生地点を特定した。さらに古い時代の地図や同じ敷地内での考古学的な発掘調査を検討したところ，この地点は池を埋め立てた場所であり，地下に砂層をふくむことがわかった。, Detailed analyses of liquefaction in historical documents help evaluations of possible future occurrences of this hazard. The 1854 Iga-Ueno earthquake caused damage in Yamashiro, which is the old name for what is now the southern part of Kyoto prefecture. Occurrence of localized liquefaction at Fushimi, which is characterized by eruption of mud and sand, and damage to a storehouse, is documented in a journal of the Bizen-Okayama domain. The site where the liquefaction occurred is located in detail by examination of historical documents and maps. The old maps and excavational investigations show that the site had been a buried pond and consists of loose sand layers. The liquefaction possibly occurred under local conditions of high groundwater level and the existence of loose sand layer.

It has long been believed that a M6.1 earthquake occurred on November 14, 1831 in Saga, southwest Japan. The event relies on a single entry from note of “Tenpo Zakki", which is a collection of miscellaneous notes between 1831 and 1844. Here we propose that the location for the earthquake is likely misinterpreted. Reexamination of the note shows that the earthquake occurred on November 13, 1831, as was recognized in 1919. The original location was thought to be in Saga because according to the note the earthquake was reported from “Hizen-no-kami” (lord of Saga). Analyses of the time it took for the news to reach Edo (Tokyo) show that the location of the earthquake is possibly not Saga, but Aizu, in northeast Japan. The note of “Tenpo Zakki” shows that the information of the event reached Edo in 5 days. However, it was impossible to deliver a letter from Saga to Edo in 5 days at that time. No description on the earthquake was found in diaries written around Saga.“Tenpo Zakki”might have mistaken“Higo-no-kami”(lord of Aizu) for “Hizen-no-kami".This result contributes to improvement of the list of historical earthquakes for Japan.

Dating of earthquakes is a basic practice in studies of historical earthquake. Incorrect dates of earthquakes sometimes occur because of (1) mistakes in the original material, (2) mistakes in compilation of material, such as historical records of local governments and collections of materials for historical earthquakes. Eight examples are presented that show the corrected dates and causes of the error. These results may help to find other misdates in historical earthquakes, which will lead to better understanding of past earthquake occurrence.

Additional file 1: Table S1. Fault model parameters of SSEs in southwest Japan estimated by Nishimura et al. (2013). Figure S1. Calculated tilt change for all fault models. Red arrows indicate the calculated tilt change due to a uniform slip of a rectangular fault shown by a blue rectangle in each panel, in which the slip vector is indicated by a blue arrow.

A mud rain event is observed in February, 1882 across a wide area of Japan's main island. Records and articles in several newspapers that written at Kyoto, Mie, Gifu, Aichi, Nagano, Tokyo, Chiba, Ibaraki Prefectures and so on, are transcribed to characterize the mud rain event. The records mostly described that something like ash, sand or mud fallen and accumulated. One article described that the night is like the one without moon. Although there was a rumor that the mud rain is caused by a volcano eruption, volcano eruption is not officially reported in the period. The point of observation seems to migrate from west to east in three days. The mud rain estimated to be brought by (1) ash fall from a volcano eruption, (2) Asian dust, or (3) local dust storm.

1856年09.月23日(旧暦安政3年08月25日)に江戸を直撃した台風について調べた｡主として安政風聞集に基づき被害状況を報告すると共に､各地の日記記録などを併せて台風の進路を含む当時の気象場を推定した｡その結果､台風は太平洋上を猛スピードで北上し相模に上陸､江戸の西側を通過して北へ抜けたと推定される｡猛烈な風による吹き寄せ効果により急激な高潮が生じたことが､人的･物的被害を拡大させた最大の要因と考えられる｡

The Zenkoji earthquake of May 8, 1847 occurred at about 9 p.m. at the area of the present city of Nagano (old territory of the Zenkoji Temple), central Japan. The earthquake caused house collapse, fire, landslides, and floods due to landslide dam breach. The 1783 eruption of Mount Asama caused ash fall and debris flow. We interpreted old documents, records, picture maps on the earthquake damage collected by Kyoto University. Summary of interpretation of one document for the 1847 Zenkoji earthquake and six for the 1783 Asama eruption is presented.

本稿は、2011年3月11日に発生した東北地方太平洋沖地震の記録を例として、巨大地震に際して記録される各種の信号を紹介する。例示する記録は、京都大学防災研究所附属地震予知研究センターに所属する各地の地殻変動連続観測室に設置された伸縮計（歪地震計）によって得られたものである。, This manuscript present geophysical signals generated by the large earthquake such as the 2011 off the Pacific coast of Tohoku earthquake. All the data presented in this manuscript were recorded with the extensometers being in operation at crustal movement observatories belonging to Research Center of Earthquake Prediction.

2008年11月から，近畿地方中北部におけるひずみ集中帯において，稠密多点臨時地震観測を行っている。本稿では，この稠密多点観測における技術的な側面を報告する。45点の臨時観測点を5年間の長期に渡って維持し，かつデータ処理を行うためには，従来技術だけでは，人的・時間的な制約上困難があった。また，45点の観測網の維持管理や，約2TB/年の大量のデータを扱うことによって生じることが懸念される人的ミスをいかに軽減するかなどの問題もあった。この観測では，京都大学防災研究所付属地震予知研究センターと株式会社近計システムの共同で開発した次世代型地震観測システム及びデータ処理装置を使用した。次世代型地震観測システムの設置，メンテナンスから，データ処理装置を利用して，回収してきた大量のデータを短期間で処理するシステムの構築，さらに観測点情報や設置・メンテナンス・データの履歴を一元管理するデータベースの開発・運用に関することを報告する。, We installed 45 temporary seismic observation stations in the middle and northern Kinki district, where active faults are concentrated. The seismometers and data loggers used are newly developed. We perform the dense observation for about four years and analyze the data together with those of permanent stations to detect heterogeneous structures related to the strain accumulation process. The purpose of the project is to clarify the relation between the strain accumulation and the earthquake generation. In this report, we described about the observation system, the data processing system, and the database system for this project.

The Zenkoji earthquake of May 8, 1847 occurred at about 9 p.m. in the present city of Nagano (old territory of Zenko-ji Temple), Central Japan. Nine faults with a total length of about 40 km appeared along the western margin of the Nagano basin. The earthquake caused house collapse, fire, landslides, flood due to collapse of dams made by landslides. We show old documents, records, picture maps on the earthquake damage, and also survey maps of the domain of Matsushiro collected by Kyoto University. The survey maps may be useful to estimate accurate distribution of the seismic intensity of the earthquake.

This manuscript introduces the data acquisition system for the continuous observation of crustal movements. The data-logger named "RL4220" was developed by us to be most suitable for our purpose. Using the RL4220, we can collect data automatically from remote places with certainty. With EWS, data collected are transformed into files of three different formats. The first of them is the "WIN format file" to be distributed. The second is to be preserved. The last is to be displayed on monitor screens. Files of the first and second format are stored in the RAID system and are able to be accessed with inter-networking.

京都大学アカデミックデイ2014 「みんなで対話する京都大学の日」[日時]2014年9月28日(日)10:00-16:00, [場所]京都大学百周年時計台記念館

[1] In situ test of hydraulic fracturing (HF) provides the only way to observe in situ stress magnitudes directly. The maximum and minimum horizontal stresses, SHmax and Shmin, are determined from critical borehole pressures, i.e., the reopening pressure Pr and the shut-in pressure Ps, etc, observed during the test. However, there is inevitably a discrepancy between actual and measured values of the critical pressures, and this discrepancy is very significant for Pr. For effective measurement of Pr, it is necessary for the fracturing system to have a sufficiently small compliance. A diagnostic procedure to evaluate whether the compliance of the employed fracturing system is appropriate for SHmax determination from Pr was developed. Furthermore, a new method for stress measurement not restricted by the system compliance and Pr is herein proposed. In this method, the magnitudes and orientations of SHmax and Shmin are determined from (i) the cross-sectional shape of a core sample and (ii) Ps obtained by the HF test performed near the core depth. These ideas were applied for stress measurement in a central region of the Kumano fore-arc basin at a water depth of 2054?m using a 1.6?km riser hole drilled in the Integrated Ocean Drilling Program (IODP) Expedition 319. As a result, the stress decoupling through a boundary at 1285?m below seafloor was detected. The boundary separates new upper layers and old lower ones with an age gap of ~1.8?Ma, which is possibly the accretionary prism. The stress state in the lower layers is consistent with that observed in the outer edge of accretionary prism.

International audience; A 1.6 km riser borehole was drilled at site C0009 of the NanTroSEIZE, in the center of the Kumano forearc basin, as a landward extension of previous drilling in the southwest Japan Nankai subduction zone. We determined principal horizontal stress orientations from analyses of borehole breakouts and drilling-induced tensile fractures by using wireline logging formation microresistivity images and caliper data. The maximum horizontal stress orientation at C0009 is approximately parallel to the convergence vector between the Philippine Sea plate and Japan, showing a slight difference with the stress orientation which is perpendicular to the plate boundary at previous NanTroSEIZE sites C0001, C0004 and C0006 but orthogonal to the stress orientation at site C0002, which is also in the Kumano forearc basin. These data show that horizontal stress orientations are not uniform in the forearc basin within the surveyed depth range and suggest that oblique plate motion is being partitioned into strike-slip and thrusting. In addition, the stress orientations at site C0009 rotate clockwise from basin sediments into the underlying accretionary prism.