著者

吉山 昭 柳田 誠

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.104, no.6, pp.809-826, 1995-12-10 (Released:2009-11-12)

参考文献数

63

被引用文献数

20 27 36

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In this paper the new methodology for quantitative estimation of uplift rates at inland region was discussed using fluvial terrace surfaces and deposit bases. Previous studies have revealed that river profiles regularly changed according to the cyclic fluctuation of climate and sealevel ; therefore, in the interglacial ages (the marine isotope stage 5e and the present) similar profiles with large concavity formed, and in the glacial ages (stage 6 and 2) linear profiles appeared on the contrary. In upper reaches of rivers, stage 5e valley bottoms were filled with the deposit accumulated in the subsequent glacial stages. Based on these observations, the value of relative height between the stage 5e burned valley bottom and the present river floor (BV value) is considered to indicate uplift during those stages (120-130 ky). Similarly, the value of relative height between the stage 6 terrace and the stage 2 terrace (TT value) can be used as an indicator of uplift during the period between those two stages.The BV values and TT values distributed along Japanese major rivers were reviewed on the basis of previous studies on terrace development and tephro-chronology. In middle reaches of most of rivers, the TT and BV values at the same sites are concordant to each other. The BV values remarkably decrease upstream in spite of no reduction of the TT values in the upper reaches or branches. This implies that present river profiles have not completely been in equilibrium and are now degrading in the upper streams and branches. As an indicator of long-term uplift rate, the TT values have the advantage of applicability to upper reaches and availability of field data in comparison to the BV value. However, it is impossible to apply these methods in the upper reaches or branches where fluvial terraces are not well developed.Up until now, the uplift rates in mountainous region were presumed from the outlined altitude of mountains or the amount of eroded material trapped in reservoirs, but have not been examined by direct data. The uplift rates obtained by using TT values and BV values are 0.10.8 mm/year in large number of sites, which are not located in very high mountainous area. Large uplift rates more than 1 mm/year were estimated from TT values at the Kurobe river basin, in the northern part of Chubu mountainous region.

著者

柳田 誠 藤原 治 後藤 憲央 佐々木 俊法

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.113, no.6, pp.835-847, 2004-12-25 (Released:2009-11-12)

参考文献数

22

被引用文献数

5 4

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The authors re-examine conventionally used terms for hills on the basis of a morphometric study of landforms in Japan. Relative relief and drainage density are calculated for every 250 m grid on topographic maps.Figure 2 shows relative relief on the vertical axis and drainage density on the horizontal axis. Hills are clearly delineated from mountains by these parameters. The relative relief for hills is smaller than 110 m120 m, and the drainage density is greater than 4050 streams/km2. The Shiranuka Hills in Hokkaido should more appropriately be called the Shiranuka Mountains, because of their high mean relative relief (134.3 m) and lower drainage density.Figure 2 also indicates a possible subdivision of hills into 2 types, or 'flat topped hills' with a relative relief of less than 60 m, and 'ridge hills' with a relative relief of 60 m 120 m. The standard deviation of relief energy can also be taken as a criterion to distinguish the 2 types of hill, namely, the flat topped hills have a standard deviation of 8.120.6, in contrast to the ridge hills, which have a standard deviation of 21.029.8.The drainage density generally increases corresponding to the length of time through which terraces are transformed into hills and the amount of uplift. Therefore, hills have greater drainage density than terraces. But, it is worthy of note that the drainage density is never greater than 7080 streams/km2. The greatest density is found in the Oku-Noto Hills, one of the ridge hills 480, 000780, 000 years old. Indications are that the development of a drainage system culminates at some stage between flat-topped hills and ridge hills, and then valleys are gradually unified, resulting in a lower drainage density.Both flat-topped hills and ridge hills may be derived from various origins such as terraces, depositional surfaces of pyroclastic flows, dissected Tertiary or early Quaternary soft rocks, or degradation of mountains with medium relief. But, the formation of ridge hills requires a greater speed of uplift, and rocks that are hard enough to sustain steep slopes with a relative relief of 80 m120 m. The conditions being the same, ridge hills are older than flat-topped hills.

著者

高田 宏宗 柳田 誠 富岡 孝仁 金井 講治 高屋 雅彦 木村 亮 影山 祐紀 竹村 昌彦 丸山 朋子 田尻 仁 松永 秀典

出版者

一般社団法人 日本総合病院精神医学会

雑誌

総合病院精神医学 (ISSN:09155872)

巻号頁・発行日

vol.25, no.3, pp.287-294, 2013-07-15 (Released:2016-12-28)

参考文献数

17

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2007年7月から2012年3月に当センターで出産した精神疾患合併妊婦137例を対象に,胎児・新生児合併症と妊娠中の服薬との関連性を検討した。流・死産7例については向精神薬服用との関連は明らかではなかった。奇形8例の母親全員が妊娠初期に向精神薬を服用していたが,妊娠12週以前に服用していた99例のうち,母体が高齢の場合に奇形発生率が有意に高かった(母体35歳以上:30例中6例,35歳未満:69例中2例,p=0.0041)。さらに,服用した向精神薬の種類数も奇形の発生に有意に相関していた(p=0.0021)。流・死産,奇形以外の合併症については,出産直前の内服によって生じ得るものとそれ以外に分けて検討した。いずれも服薬群のほうが非服薬群より発生頻度が約50%高かった。本研究から妊娠初期に向精神薬を内服していた症例では,高齢妊婦および多剤併用という2つの因子が奇形発生のリスクを高めることが示唆された。

著者

田力 正好 安江 健一 柳田 誠 古澤 明 田中 義文 守田 益宗 須貝 俊彦

出版者

公益社団法人 日本地理学会

雑誌

地理学評論 Series A (ISSN:18834388)

巻号頁・発行日

vol.84, no.2, pp.118-130, 2011-03-01 (Released:2015-09-28)

参考文献数

30

被引用文献数

3 2

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岐阜県南東部および愛知県西部を流れる土岐川(庄内川)流域の河成段丘を,空中写真判読によりH1~4面,M1~3面,L1~3面の10段の段丘面に分類した.それらの段丘面のうち,L2面は,構成層中の試料の14C年代値,構成層を覆う土壌層中の指標テフラ(鬼界アカホヤテフラ),段丘面の縦断形と分布形態,段丘構成層の厚さに基づいて,酸素同位体ステージ(MIS)2の堆積段丘面と同定された.M2面は構成層と指標テフラ(阿蘇4テフラ,鬼界葛原テフラ)との関係,構成層およびそれを覆う風成堆積物の赤色風化に基づいて,MIS6の堆積段丘面と同定された.これらのことから,これまでMIS6の堆積段丘の報告がほとんどなかった中部地方南部において,その分布が確認された.M2面とL2面の比高から,土岐川流域の隆起速度は0.11~0.16 mm/yrと求められた.

著者

池田 倫治 柳田 誠 西坂 直樹

出版者

日本活断層学会

雑誌

活断層研究 (ISSN:09181024)

巻号頁・発行日

vol.2012, no.36, pp.31-44, 2012

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The Mw 7.1 (GNS Science) earthquake (Darfield earthquake) occurred near Christchurch, New Zealand on 4 September 2010. The earthquake happened in the area where active faults had not recognized previously, produced the ground surface rupture (Greendale fault). We surveyed the mode of occurrences of the Greendale fault on 8 days after the Darfield earthquake. Measured dextral and vertical displacements along the fault are ~ 4.2 and ~ 1.5 m (predominantly southern parts up), respectively. The both slip components are distributed roughly symmetrically along the west fault segment. However, the maximum displacement points are perhaps different between dextral and vertical sense based on the survey results. The fault is roughly E–W strike, characterized by many Riedel fractures that show shapes of mole tracks accompanying main dextral displacements. Few active faults had recognized previously on Canterbury plain near Christchurch, whereas distribution of active faults and folds had cleared in the Pegasus Bay area where locates in the eastern part of the Christchurch. Moreover, there are records of a few paleoearthquakes (M>5) near Christchurch and in Pegasus Bay. These data would have been clues to forecast existence of blind active faults on Canterbury plain.

著者

吉山 昭 柳田 誠

出版者

学術雑誌目次速報データベース由来

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.104, no.6, pp.809-826, 1995

被引用文献数

30 27

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In this paper the new methodology for quantitative estimation of uplift rates at inland region was discussed using fluvial terrace surfaces and deposit bases. Previous studies have revealed that river profiles regularly changed according to the cyclic fluctuation of climate and sealevel ; therefore, in the interglacial ages (the marine isotope stage 5e and the present) similar profiles with large concavity formed, and in the glacial ages (stage 6 and 2) linear profiles appeared on the contrary. In upper reaches of rivers, stage 5e valley bottoms were filled with the deposit accumulated in the subsequent glacial stages. Based on these observations, the value of relative height between the stage 5e burned valley bottom and the present river floor (BV value) is considered to indicate uplift during those stages (120-130 ky). Similarly, the value of relative height between the stage 6 terrace and the stage 2 terrace (TT value) can be used as an indicator of uplift during the period between those two stages.<BR>The BV values and TT values distributed along Japanese major rivers were reviewed on the basis of previous studies on terrace development and tephro-chronology. In middle reaches of most of rivers, the TT and BV values at the same sites are concordant to each other. The BV values remarkably decrease upstream in spite of no reduction of the TT values in the upper reaches or branches. This implies that present river profiles have not completely been in equilibrium and are now degrading in the upper streams and branches. As an indicator of long-term uplift rate, the TT values have the advantage of applicability to upper reaches and availability of field data in comparison to the BV value. However, it is impossible to apply these methods in the upper reaches or branches where fluvial terraces are not well developed.<BR>Up until now, the uplift rates in mountainous region were presumed from the outlined altitude of mountains or the amount of eroded material trapped in reservoirs, but have not been examined by direct data. The uplift rates obtained by using TT values and BV values are 0.10.8 mm/year in large number of sites, which are not located in very high mountainous area. Large uplift rates more than 1 mm/year were estimated from TT values at the Kurobe river basin, in the northern part of Chubu mountainous region.