Article https://doi.org/10.1007/s12303-020-0032-9 pISSN 1226-4806 eISSN 1598-7477 Geosciences Journal GJ Estimating the potential risk of the Mt. Baekdu Volcano using a synthetic interferogram and the LAHARZ inun- dation zone Arief R. Achmad 1 , Seulki Lee 1 , Sungjae Park 1 , Jinah Eom 2 , and Chang-Wook Lee 1 * Division of Science Education, Kangwon National University, Chuncheon 24341, Republic of Korea Research Institute for Earth Resources, Kangwon National University, Chuncheon 24341, Republic of Korea ABSTRACT: The Baekdu Volcano is located on the border between Jilin Province, China, and Ryanggang Province, North Korea. Its 946 AD eruption had a Volcanic Explosivity Index (VEI) of 7, making it among the most massive eruptions in the past 2000 years, a “Millennium eruption”. Mount Baekdu may erupt in the near future. To examine the future impact of Mount Baekdu, we generated a synthetic interferogram using a Mogi model equation to produce a simulated surface deformation phase and added simulated orbital error, topographic error, and atmospheric effects phases. We output the simulation results to the program LAHARZ, which can gen- erate a potential hazard zone due to lahar flow. Using LAHARZ, the area affected by a Baekdu lava flow would be 4.575, 14.522, 15.866, 60.351, 404.848, 3,019.298, and 6,001.885 km 2 with a VEI scale eruption of 1 to 7, respectively, while the synthetic interferogram showed that the simulated surface deformation at Mount Baekdu would be 0.04 cm, 0.1 cm, 0.7 cm, 10 cm, 1 m, 12 m, and 100 m according to the VEI category. This study can be used to estimate the interferometric synthetic aperture radar (SAR) surface defor- mation of Mount Baekdu and produce a hazard inundation zone map with a more certain lahar flow volume in an actual volcanic eruption and surface deformation detected using SAR images on inflation of the magma chamber. Key words: LAHARZ, Mogi model, mount baekdu, simulation, synthetic interferogram Manuscript received August 13, 2020; Manuscript accepted August 31, 2020 1. INTRODUCTION Mount Baekdu is a stratovolcano located in the Changbai Mountains on the Chinese–North Korean border that has a 2744 m peak and also known as Changbaishan in China. This volcano is renowned because it had a major eruption (Xu et al., 2013) with a substantial climatic impact around 946 AD (Li et al., 1996; Guo et al., 2002) with a Volcanic Explosivity Index (VEI) of 7 (Yin et al., 2012), similar to the eruption of Mount Tambora in Indonesia (Wei et al., 2003). A massive explosive eruption could lead to global catastrophe (Yin et al., 2012). Because of the high danger level, frequent monitoring is necessary to anticipate the impact of a catastrophic near-future eruption. Monitoring can be performed using remote sensing data, such as monitoring the volcanic activity by applying anomaly thermal data over volcanoes from remote sensing products, including near-infrared or thermal imagery (Vaughan and Hook, 2006). The volcanic activity could also be monitored using synthetic aperture radar (SAR), especially for Mount Baekdu (Massonnet et al., 1995; Hong, 2018; Park and Lee, 2019). Based on the interferometric SAR (InSAR) theory developed by Zebker and Goldstein (Zebker and Goldstein, 1986), InSAR corrected using a topographic phase known as the differential InSAR (DInSAR) technique could be used to monitor volcanic activity, and is applied as the first approach in this study. Another advanced analysis using SAR data is a multi-temporal interferogram framework that provides time-series measurements of deformation and more information about volcanic activity with high temporal resolution, such as persistent scatterer interferometry (Ferretti et al., 2001; Hooper, 2008; Hooper et al., 2012) and small-baseline DInSAR (Berardino et al., 2002; Lee et al., 2010; Lee et al., 2013; Lee, 2014). Using DInSAR, Mount Baekdu was subsiding by up to 9 cm/ *Corresponding author: Chang-Wook Lee Division of Science Education, Kangwon National University, 1 Gang- wondaehakgil, Chuncheon 24341, Republic of Korea Tel: +82-33-250-6731, Fax: +82-33-259-5600, E-mail: cwlee@kangwon.ac.kr The Association of Korean Geoscience Societies and Springer 2020