FONT SIZE:
尾瀬地域におけるアカシボの発達過程
福原, 晴夫;木村, 直哉;北村, 淳;落合, 正宏;山本, 鎔子;林, 卓志;大高, 明史;小島, 久弥;福井, 学;菊地, 義昭;野原, 精一
Permalink : http://hdl.handle.net/2115/49011
KEYWORDS : アカシボ;尾瀬ヶ原;尾瀬沼;アカユキ;土壌―雪界面;Akashibo;Ozegahara Mire;Lake Ozenuma;red snow;soil-snow interface
Abstract
尾瀬地域では尾瀬ヶ原と尾瀬沼に大規模なアカシボが発生する. 尾瀬ヶ原では融雪の後期に雪原表面が赤褐色に彩色し, 次第に濃さを増していく. この発達段階を雪コアーの肉眼的観察から(1)アカシボ初期（Stage 1；雪原表面は白, アカシボ雪が積雪の半分以下）, (2)アカシボ中期（Stage 2；雪原表面は白またはわずかに赤色, アカシボ雪は積雪の半分以上）, (3)アカシボ最盛期（Stage 3；積雪全体がアカシボ雪, プール形成）, (4)アカシボ終期（Stage 4；浮遊状態や植物体, 土壌表面（底泥）に付着する）, (5)アカシボ残存期（Stage 4；アカシボ残存物が土壌表面に存在する）に分けて整理した. 尾瀬沼においては融雪水と湖水位の上昇により, アカシボを含んだ氷雪が湖面に浮上するため, stageは明確ではないが, 同様に発達をすると考えられる.
A large scale of red snow phenomena “Akashibo”appeared at Ozegahara Mire and Lake Ozenuma in Oze District during snow melting period. Five developmental stages of Akashibo are classified. (1)The first stage (Stage 1;white snow surface, the lower half of the snow depth colored reddish), (2) the middle stage (Stage 2; white snow surface or faintly colored,strongly red in the lower section (above about half of the snow accumulation), (3)the peak stage (Stage 3;entire snow patches are dark-red),(4)the end stage (Stage 4;accumulation of fresh Akashibo substances on soils or dead plants) and (5) the residual stage (Stage 5; Akashibo substances remaining on soils to fall). Development of Akashibo at Lake Ozenuma seemed to be essentially same as Ozegahara Mire, but showed unclear stages, because of rising lake water level.
A large scale of red snow phenomena “Akashibo”appeared at Ozegahara Mire and Lake Ozenuma in Oze District during snow melting period. Five developmental stages of Akashibo are classified. (1)The first stage (Stage 1;white snow surface, the lower half of the snow depth colored reddish), (2) the middle stage (Stage 2; white snow surface or faintly colored,strongly red in the lower section (above about half of the snow accumulation), (3)the peak stage (Stage 3;entire snow patches are dark-red),(4)the end stage (Stage 4;accumulation of fresh Akashibo substances on soils or dead plants) and (5) the residual stage (Stage 5; Akashibo substances remaining on soils to fall). Development of Akashibo at Lake Ozenuma seemed to be essentially same as Ozegahara Mire, but showed unclear stages, because of rising lake water level.
FULL TEXT:PDF