1 0 0 0 桜島火山

著者
小林 哲夫 佐々木 寿
出版者
The Geological Society of Japan
雑誌
地質学雑誌 (ISSN:00167630)
巻号頁・発行日
vol.120, pp.S63-S78, 2014
被引用文献数
3

桜島火山は鹿児島湾最奥部を占める姶良カルデラの後カルデラ火山であり,その誕生は26,000年前である.歴史時代にも多くの噴火を繰り返したが,ちょうど100年前の大正噴火(1914年)で流出した溶岩で瀬戸海峡が埋め立てられ,大隅半島と陸続きとなったのは有名である.その後も山頂~山頂付近に生じた火口で活発な噴火活動を続けており,日本を代表する活火山である.本コースでは,桜島火山の歴史時代の噴出物や最新の火山地形を観察する.特に大正噴火の西側火口から噴出した火砕物質と溶岩流の産状を詳しく観察し,噴火の推移を考える.
著者
小林 哲夫
出版者
The Japanese Society of Fish Pathology
雑誌
魚病研究 (ISSN:0388788X)
巻号頁・発行日
vol.14, no.4, pp.151-157, 1980-04-30 (Released:2009-10-26)
参考文献数
15

This is a report concerning the diseases in artifical salmon propagation programme in Hokkaido. Although the diseases during the artificial propagation of salmons are usually not so frequent as those in fish culture, the preventive and restraint of them are indispensable to the salmon propagation on account of their artificial mass production.It has been widely known that almost all the diseases of salmon resulted in the mass mortalities are caused by well described microorganisms. Furunclosis caused by Aeromonas salmonicida occurs often in the immature adult fish kept in a holding pond untile they reach maturity. Bacterial kidney disease has now been recongnized in cultured salmon.Infections with Saprolegnia sp. and Achlya sp. have been usually found in adult fish of salmons holding pond. Although most of the saprolegnoid infections are generally considered to be secondary condition, kokanee salmon, Oncorhynchus nerka var. adonis, has been heavily infected with Saprolegnia shikotsuensis sp. nov. from 1974 to 1978, except 1976.Gill diseases caused by various bacterial species or protozoa are found frequently in salmon fry. Especially, in chum salmon fry bacterial gill idseases tend to increase recently along with the diffusion of fry feeding.Among the virus diseases that occur in salmonid in epizootic proportions, so far only IHN is found in masu salmon and kokanee salmon at times, but it is still not recorded in chum salmon fry in Hokkaido.External protozoan disease caused by Tricodina sp. is usually not so frequent and serious as the bacterial and virus diseases.
著者
福島 大輔 小林 哲夫
出版者
特定非営利活動法人 日本火山学会
雑誌
火山 (ISSN:04534360)
巻号頁・発行日
vol.45, no.4, pp.225-240, 2000
参考文献数
38
被引用文献数
2

The Tarumizu pyroclastic flow deposit with intercalation of Osumi plinian fall deposit of 25 ka eruption is distributed in Tarumizu area, southeast of Aira caldera. The deposit is composed of many flow units and the source is estimated to be at the same position as the vent of plinian eruption based on grain-size variation and depositional structure. From these facts, the Tarumizu pyroclastic flow is considered to be a type of intra-plinian fiow generated by successive partial collapse of the sustained plinian eruption column. Based on the stratigraphic suecessions, the generation of this flow is estimated to be a continuous process from the early to the terminal stage of the plinian eruption. The pyroclastic flow distribution, which is in the same direction with the dispersal axis of plinian fall deposit, may suggests that the wind influenced the direction of partial column collapse. Two lithofacies were identified in the Tarumizu pyroclastic flow deposit: the massive facies and the stratified facies. The former is a 'normal' pyroclastic flow, while the latter is a pile-up of many thin layers of pyroclastic flow and pumice fall. The massive facies are mainly distributed on the lower plain near the coast and differ from the stratified facies that accumulated at a bit higher level, usually along the foot of the mountain. These facts suggest that the main pyroclastic flow accumulated on the lower level and that the corresponding marginal part of the flow eventually reached the higher level exhibiting characteristic thin stratified structure.
著者
小林 哲夫
出版者
水文・水資源学会
雑誌
水文・水資源学会誌
巻号頁・発行日
vol.9, no.3, pp.280-284, 1996

自然状態下の土壌中では,液体水と水蒸気が局所熱力学的平衡状態にあると見なせることは既に確認されている(Milly, 1982).本報では,蒸発時には,土壌表面およびその近傍においても局所平衡が成り立つと見なせることが明らかにされる.この結果は,数値気象・気候モデルにおいて土壌表面の含水率から"表面湿度"を推定するために提案された多くの実験公式が,熱力学的平衡公式(本文式(7))に代わるもの(Lee and Pielke, 1992)ではなく,水蒸気の移動に対する抵抗の影響を強く受けた物理的意味の乏しい経験公式であることを示唆する.
著者
田島 靖久 松尾 雄一 庄司 達弥 小林 哲夫
出版者
特定非営利活動法人日本火山学会
雑誌
火山 (ISSN:04534360)
巻号頁・発行日
vol.59, no.2, pp.55-75, 2014

The Kirishima volcanoes located in southern Kyushu are comprised of more than 20 volcanic edifices. The volcanoes occupy an elliptical area of approximately 330km^2 with the WNW-ESE direction. Among the different types of volcanic edifices, the typical ones are compound maars and lava flows in Ebinokogen. We studied the volcanic history of Ebinokogen by geological examination of tephra layers and lava flows. After the Karakunidake-Kobayashi plinian eruption, seven tephra were formed in this area. We determined the ages of those tephra and two lava flows. The magmatic eruptions, produced Tamakino B tephra, occurred after Karakunidake-Kobayashi tephra eruption. The first activity in Ebinokogen from about 9.0 cal ka BP generated Fudoike lava flow, and Fudoike-Tamakino A tephra erupted from Fudoike crater. Karakunidake north-Ebino D tephra was generated from the northwest flank of Karakunidake at 4.3 cal ka BP, with debris avalanche and lahars. Phreatic Fudoike-Ebino C tephra erupted from the Fudoike crater at 1.6 cal ka BP. Ioyama-Ebino B tephra eruption started from around the 16^<th> to 17^<th> century with lava flow. Phreatic Ioyama east-Ebino A tephra erupted from Ioyama east crater in 1768 AD. The Ebinokogen area is one of the active regions of Kirishima volcanoes explicated by geophysical observations. Our results indicate cyclical tephra depositions mainly produced by small magmatic and strong phreatic eruptions in this area after the Karakunidake-Kobayashi pyroclastic eruption. Furthermore, the vent locations were found to migrate with each eruption.
著者
小林 哲夫 早川 由紀夫 荒牧 重雄
出版者
The Volcanological Society of Japan
雑誌
火山.第2集 (ISSN:24330590)
巻号頁・発行日
vol.28, no.2, pp.129-139, 1983-07-01 (Released:2018-01-15)

大隅降下軽石堆積物は, 約22, 000年前に鹿児島湾最奥部で起こった一連の巨大噴火の最初期のプリニアン噴火の産物である.灰白色の軽石と遊離結晶および少量の石質岩片からなる本堆積物は, 全層にわたってほぼ均質な見かけを呈するが, 多くの場合, 上方に向かって粒径がやや大きくなる逆級化層理を示す.層厚分布図(Fig.3)と3種の粒径分布図(軽石の平均最大粒径・石質岩片の平均最大粒径・堆積物の中央粒径;Figs.5, 6, 7)は, いずれも本堆積物の噴出火口が姶良カルデラの南縁, 現在桜島火山の位置する地点付近にあったことを示している.分布軸は火口からN120°E方向に伸びるが, 分布軸から60 km以上離れた地点にも厚く堆積している.又, 堆積物は分布軸の逆方向すなわち風上側にも20 km以上追跡できる.分布軸上で火口から30 km離れた地点での層厚は10 mに達するが, 40 km地点より遠方は海域のため層厚値は得られない.そのため噴出量の見積もりには多くの困難が伴うが, すでに知られている他のプリニアン軽石堆積物の層厚-面積曲線(Fig.4)にあてはめて計算すると, 総体積98 km3(総重量7×1016g)が得られ, 本堆積物は支笏-1軽石堆積物(116 km3)に次ぐ最大規模のプリニアン軽石堆積物であることがわかる.3種の粒径分布図から得られる粒径-面積曲線(Fig.8)は, 噴出速度・噴煙柱の高さ・噴出率などで示される噴火の「強さ」を比較する上で有効である.それにより, 大隅降下軽石噴火の「強さ」はけっして例外的なものではなく, プリニアン噴火の平均あるいはそれをやや上回る程度であったことが判明した.
著者
小林 哲夫
出版者
日本地質学会
雑誌
地質学論集 (ISSN:03858545)
巻号頁・発行日
no.24, pp.93-107, 1984-11-30
被引用文献数
6

Yufu-Tsurumi volcanoes are situated at the northeastern part of Kyushu island, Japan. Lavas and pyroclastic rocks ranging from the late Pliocene to the late Quaternary in age form the basemment of this area and are cut by many active faults bringing about the blocks tilted variously. Judging from the tephrochronology of the wide-spread tephra, it has been confirmed that both Yufu and Tsurumi volcanoes started their activities more than 35,000 years ago. Yufu-dake is a stratovolcano with several parasitic lava domes and lava flows. The latest eruption occurred ca. 2,000-1,500 years ago issued the Tsukahara pyrodastic flow, the Ikeshlro lava, the Yufu-dake summit lava, and the Yufu-dake ash. The Tsukahara pyroclastic flow deposit is oxidized under the high temperature condition and has secondary fumarolic pipes. The Tsukahara pyroclastic flow is judged to have been formed by the collapse of an ascending lava dome. Stratigraphic relation between the pyroclastic flow and the volcanic ash shows that the collapse of the lava dome happened repeatedly at least two times. The last ascending of lava formed the Ikeshiro lava dome accompanied with lava flow. Shortly after that, the Yufu dake summit lava was issued and formed a summit lava dome. All the activities mentioned above represent a single cycle of eruption ceased within a short period of time. Based on the documentary record, however, it is convinced that the fumarolic activity was continued until the time ca. 1,100 years ago. Tsurumi volcano is composed of highly dissected volcanic edifice and the younger parasitic volcanoes. Based on the tephrochronology of wide-spread tephra, the younger parasitic volcanoes other than the Tsurumi-dake summit lava are judged to have been formed during the period of time ranging from 22,000 to 6,300 years before present. Garan-dake, Uchi-yama, and Nanpeidai are all lava domes and Oninomi-yama alone is a scoria cone with basaltic lava flow. The Tsurumi-dake summit lava which filled up the summit crater and formed a summit lava dome flowed down southward and eastward. One of the lobes of lava flow dammed up the river resulting in the developemment of a volcanic fan formed from the tip of a lava flow. Judging from the distrbution pattern of historic sites on the fan and the descriptions in the ancient manuscripts, it is reasonably concluded that the lava was issued about 1,500-1,200 years ago. Most of the rocks in this area is hornblende andesite ordacite, but a complicated assemblage of phenocryst, namely the olivine-clinopyroxene-orthopyroxene-hornblende-biotite-quartz-plagioclase-Fe-Ti oxides is frequently found in the rocks of of these volcanoes.
著者
小林 哲夫
出版者
特定非営利活動法人日本火山学会
雑誌
火山. 第2集 (ISSN:04534360)
巻号頁・発行日
vol.30, no.1, pp.45-47, 1985-04-01
著者
奥野 充 小林 哲夫
出版者
Japan Association for Quaternary Research
雑誌
第四紀研究 (ISSN:04182642)
巻号頁・発行日
vol.33, no.2, pp.113-117, 1994
被引用文献数
1 4 8

種子島には阿多 (Ata), 鬼界葛原 (K-Tz), 姶良Tn(AT)などの後期更新世テフラが分布する. 長岡 (1988) は, K-TzとATの間に種I火山灰, 種II軽石, 種III火山灰を記載している. 筆者らは, 種IIの上位に2枚の火山灰層を認めたので, これらを下位から種III火山灰, 種IV火山灰と呼ぶ. 種Iは橙色の細粒降下火山灰, 種IIは淡黄褐色の降下軽石であり, 両者とも種子島北部に分布する. 種III火山灰と種IV火山灰は, 黄褐色~橙色の細粒降下火山灰で, どちらも種子島全域に分布する. 噴出年代は, K-TzとATとの層位関係から, 種Iと種IIが65ka, 種IIIが45ka, 種IVが35kaと推定される. 斑晶鉱物の組合せ, 斜方輝石(γ)の屈折率および層位から, 種IIは阿多カルデラ周辺に分布する唐山スコリア (Nagaoka, 1988) に対比される.