Anomalous Variation of Water Temperature and Evolution of Gas at Ye-gawa, Tokusima Prefecture, Japan

[摘要] Ye-gawa (or Ye-kawa, ye: pond, kawa or gawa: river) is a branch of Yosino-gawa (one of the greatest river of Japan). Long and narrow ponds (depth 0.5-1 meter) constitute the head-water of Ye-gawa and there gushes much water at the bottom of the ponds. The water temperature there falls to about 9° on summer days when the air temperature rises as high as about 30° (July-August), and rises to 22° on winter days when the air temperature falls as low as 2-3° (December-January). Such variation of water temperature is extraordinary and moreover when the water temperature reaches the maximum, abundant evolution of gas begins and when it approaches the minimum, evolution of gas ceases. The gas bubbles are observed at the bottom of the ponds and seem to follow the gush of water. The chemical composition of the gas coincides nearly with that of the atmospheric air (see Table 1 in the text). The mechanism of such anomalous temperature variation and seasonal evolution of gas is given on some assumptions. The former is presumably attributed to the alternation of underground water and the latter to the atmospheric air mechanically swallowed up by the underground water at some other places.

[学科分类] 大气科学