著者
早川 裕一 松倉 公憲
出版者
公益社団法人 東京地学協会
雑誌
地学雑誌 (ISSN:0022135X)
巻号頁・発行日
vol.112, no.4, pp.521-530, 2003-08-25 (Released:2009-11-12)
参考文献数
26
被引用文献数
7 11 1

The mean recession rate of Kegon Falls is examined, estimating original location and age. Two locations (LI and LII) at which the waterfall originated are estimated based on the distribution of Kegon lava, while the age of origination is considered to be the same as that of the Kegon lava eruption, i.e., 20, 000 years ago. Two values of the mean recession rate obtained are 0.018 m/y for the case of LI and 0.10 m/y for the case of LII. On the other hand, the recession rate can be evaluated, as an order estimation, using the empirical equation of the authors (Hayakawa and Matsukura, Earth Surf. Process. Landforms, 28, 2003), which shows relationships between the recession rates of waterfalls and the ratio of the erosive forces of rivers to bedrock resistance. The values of parameters used in the index of force/resistance ratio are obtained from existing data and field measurements for Kegon Falls. Substituting them into the equation, the recession rate is calculated to be in the order of 0.009-0.019 m/y. This result suggests that the recession rate for the case of LI is suitable for Kegon Falls.
著者
松倉 公憲
出版者
公益社団法人 東京地学協会
雑誌
地学雑誌 (ISSN:0022135X)
巻号頁・発行日
vol.126, no.3, pp.271-296, 2017-06-25 (Released:2017-08-03)
参考文献数
131
被引用文献数
3 6

A brief review of our weathering studies is presented, specifically from a geomorphic perspective. The review suggests that experimental work and microscale investigations using new analytical methods have advanced studies on weathering processes, while steady advances have been made in research on changes in properties and rates of weathering. Assignments and priorities are presented arising from our studies, including the need to: (1) accumulate data on rates of change of rock properties due to weathering (especially strength reduction); and, (2) construct a geomorphological equation of weathering rates based on the relationship between weathering processes and rock properties.
著者
青木 久 松倉 公憲
出版者
日本地形学連合
雑誌
地形 (ISSN:03891755)
巻号頁・発行日
vol.25, no.3, pp.267-276, 2004-07-25
被引用文献数
8

We introduce the equotip hardness tester and present the relations between the Equotip rebound value (L-value) and the unconfined compressive strength (UCS) for intact rock samples. Based on existing data and the results of our laboratory tests, an equation is derived connecting UCS (MPa) and L-value obtained from single impacts, L_s, and porosity, n (%), using multiple linear regression analysis: it is found that UCS = 0.079 e^<-0.039n> L_s^<1.15>
著者
松倉 公憲 青木 久
出版者
日本地形学連合
雑誌
地形 = Transactions, Japanese Geomorphological Union (ISSN:03891755)
巻号頁・発行日
vol.25, no.2, pp.175-196, 2004-04-25
参考文献数
147
被引用文献数
11

We briefly review some problems arising in papers on the Schmidt hammer used in a geomorphological context. There are several types of Schmidt hammer, and many measurement methods including ways of collecting data have beeen proposed, but no standard method for taking measurerements has yet been established. We propose continueous (repeated) impacts for assessing the hardness of intact rock and single impact for assessing the hardness of a rock surface, including the weathering layer.
著者
早川 裕弌 松多 信尚 前門 晃 松倉 公憲
出版者
日本地形学連合
雑誌
地形 (ISSN:03891755)
巻号頁・発行日
vol.34, no.1, pp.21-36, 2013-01-25

Recession rates of four waterfalls formed by the surface deformation of the Chelungpu Fault at the time of Chi-Chi Earthquake on September 21, 1999 in central Taiwan were measured in the field and assessed with an empirical model of waterfall erosion. The model represents the balance between the erosive force of streams versus bedrock resistance with relevant environmental parameters of discharge (drainage area and precipitation), waterfall form and bedrock strength. The recession rates of three waterfalls increased from the first 6 years to the following 4 years. This increase in the recession rates basically corresponds to the changes in environmental factors including precipitation increase and waterfall width narrowing. The recession rate of another waterfall decreased, but this can be explained by artificial modification of riverbed. The recession rates are very high comparing with waterfalls in other places, probably due to large amount of hard gravels transported on the weak bedrock from the upstream areas.
著者
鈴木 隆介 八戸 昭一 田中 幸哉 松岡 憲知 松倉 公憲 砂村 継夫
出版者
中央大学
雑誌
基盤研究(C)
巻号頁・発行日
1998

本研究の目的は,2001年8月23〜28日に日本で開催されるIAG第5回国際地形学会議における「岩石制約論シンポジウム」の基調報告の内容および討論課題を設定し,報告者の選定ならびに同シンポジウムに直結する野外巡検候補地の選定のための企画調査である.その成果を以下に要約する.1) 文献調査「地形形成過程における岩石物性の役割」を定量的に研究した成果を,世界の主要な学術雑誌,国際会議報告書および既刊書などについて,計254編の文献を収集・整理した.その結果, 「岩石制約論シンポジウム」の討論課題としては,総論,各論および岩石物性測定法の三部に大別し,総論では岩石制約論の根本課題の総括,各論では河川侵食過程,海岸侵食過程,マスムーブメント,氷河・周氷河過程,斜面発達,岩盤風化のそれぞれに関連する岩石制約の実例の総括,そして岩石物性測定法では野外測定法と室内測定法の諸問題,をそれぞれ主題および副題とすることとした.各部門と副題のオーガナイザーとしては本研究組織の全員が分担し,外国人では1999年末までの予備登録者の中から選定し,個別折衝して,最終的には2001年1月までに決定することとした.2) 野外巡検の企画日本で岩石制約論的観点からの研究成果が累積している北海道豊富町付近,福島県東部海岸,秩父盆地,千葉県各地,三浦半島,宮崎県南東部について,各地区ごとに本研究組織の研究者が現況を確認した.その結果,野外巡検地としては房総地域(4日間)と北海道豊富地域(5日間)の2地域とし,第5回国際地形学会議のFirst Circularに掲載・発送した.3) Proceedings刊行の企画「岩石制約論シンポジウム」の成果をまとめて英文単行本として出版することとした.