SHRIMP zircon U-Pb ages and Caldera formation process of the Goro volcanic complex in Eastern Gunwi, Korea

Conceptualizing a multi‐layered shingle aquifer model based on volcanic stratigraphy and water inflow to lava caves in Jeju Island, Korea

“…In the present study, we observed water flowing into Manjanggul and Yongcheondonggul (“‐gul” and “‐donggul” refer to caves in Korean), corresponding to the mid‐ to downstream sections of the Geomunoreum Lava Tube System, which are located in the coastal area (Figure 1). Manjanggul is 7.4 km in length, with the depth from the ground level to the cave ceiling ranging from 3.4 to 32.0 m. The height and width of this cave range from 2.0 to 23.0 m and from 3.4 to 21.3 m, respectively, and the elevation of the cave bottom ranges from 86 to 54 m asl (Ahn & Hwang, 2008). Yongcheondonggul's length is 3.4 km, including an 800‐m underwater portion extending into the sea, the depth from the ground level to the cave ceiling ranges from 2.2 to 14 m, the height and width of the cave range from 1.7 to 12 m and from 3 to 13.5 m, respectively, and the elevation of the cave bottom ranges from 6.6 to 49 m asl excluding the underwater portion (JSS‐GP, 2011, unpublished).…”

“…Water inflow in Yongcheondonggul and Manjanggul was monitored on September 26 and October 3, respectively, after two typhoons, Tapah (22 September 2019) and Mitag (2 October 2019), passed Korea accompanying heavy rainfall (Figure 2). The locations of water inflow were determined using the Manjanggul survey map published by Ahn and Hwang (2008) and the Geomunoreum Lava Tube System survey map from Jeju Special Self‐Governing Province (JSS‐GP, 2011, unpublished). To assess the geological characteristics of the area surrounding each cave and determine the horizontal extent of the palaeosol, this study used drilling data obtained around Yongcheondonggul and Dangcheomuldonggul (JSS‐GP, 2009, unpublished).…”

“…Water inflow in Yongcheondonggul and Manjanggul was monitored on September 26 and October 3, respectively, after two typhoons, Tapah (22 September 2019) and Mitag (2 October 2019), passed Korea accompanying heavy rainfall (Figure 2). The locations of water inflow were determined using the Manjanggul survey map published by Ahn and Hwang (2008) and the Geomunoreum Lava Tube System survey map from Jeju Special Self-Governing Province (JSS-GP, 2011, unpublished).…”