• Journal of the Korean Geographical Society
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• v.43 no.4
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• pp.466-476
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• 2008

Gurin Cave, 442 m long, is a lava tube developed on the northern slope of Mount Halla. Seventy-three meters of its lower reach became a river channel since Byeongmun River flowed into a window after roof collapse took place. The subterranean channel has a width of 447 cm and a height of 501 cm, respectively. Its banks show well-developed lava shelves of a typical lava tube, while its floor has sculpted forms which characterize a bed of a bedrock stream. The reach is likely to be collapsed and then has four collapsed windows since its roof has the densely developed testudinal joints and consists of thin lavas with a thickness of 30 to 60 cm. Before the subterranean channel appeared, a ground channel flowed over the cave and joined into a main channel of Byeongmun River at 653 m in altitude. However, the subterranean channel substituted the ground channel since a bed of the ground channel collapsed into the cave. The new channel, flowing through the cave, joined into a main channel at 660 m in altitude. As the drainage area of Byeongmun River expanded upstream the cave, the new channel changed into a main channel. Since floodwater flows down the ground channel as well as the subterranean channel, a distributary stream has temporarily appeared at the collapsed window. Lava tubes are likely to have an affect on the development of river system in Jeiu Island, in that the caves have constantly shown roof-fall.

• Journal of The Geomorphological Association of Korea
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• v.19 no.2
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• pp.17-29
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• 2012

In order to improve a trip pattern in Mt. Halla climbing only to a summit, two trip programs with nature interpretation have been developed using the geomorphic characteristics of Mt. Halla which are distinct from those of mountains in the Korean peninsula. It also aims to help conservation of natural environment of Mt. Halla and to enhance the visitor satisfaction in Mt. Halla. The subalpine trip program is carried out on a 1.5 km-long trail between Wissaeoreum Hut and Janggumokoreum. Program participants are able to learn expertise about, and understand vulnerability of, a subalpine ecosystem, Consequently, the program can obtain an educational attainment getting them to recognize the necessity of preserving the subalpine zone of Mt. Halla as an important natural resource. The mountain river trip program is performed on a 1.5 km-long reach of Byeongmun River between Gwaneumsa trailhead and a gorge upstream of Gurin Cave. The program is capable of exhibiting effectively the river characteristics of Jeju Island using the geomorphic and hydrologic properties of Byeongmun River which differ from those of rivers in the Korean peninsula. Since the subalpine grassland and ephemeral stream of Mt. Halla are the visiting places which are rarely experienced in the Korean peninsula, the program participants can understand the regionality of Jeju Island as well as Mt. Halla through trip activities.