## 1 Introduction  
While recent studies have evaluated the characteristics of seismic response spectrum and seismic design mainly in the inland areas on the Korean Peninsula ([PERSON] et al., 2016; [PERSON] et al., 2016; [PERSON] et al., 2018; [PERSON] et al., 2018), none have studied seismic design in Jeju Island, the southernmost part of the Korean peninsula [1, 2, 3, 4]. Areas surrounding Jeju island are seismically less active or fairly weak considering no large historical earthquakes (ML greater than 5.0) have been recorded in those regions. However, seismic design is mandatory for major national infrastructures and utilities. Owing to the recent development of tourist facilities, a second airport is specifically being planned in Jeju island within a short period of time to cope with the rapid increase in the population. Furthermore, there is an increasing demand for large-scale utility facilities with large capacity such as nuclear power plants. Considering this, there has been an increasing need for studies evaluating the seismic design unique to this area. This study is the first to evaluate the seismic design in areas surrounding Jeju island. We investigated the response spectrum for the seismic design criterion according to the seismic characteristics of the Jeju area and compared the results with that of the seismic design of inland areas. Jeju Island, located approximately 70 km (EW) and 30 km (NS) on the continental shelf south of the Korean peninsula, is a volcanic island with geochemical characteristics of oceanic island basalt ([PERSON], 2000), formed by the Pleistocene eruption [5]. Jeju is geologically much different from the inland areas. The island includes the Halla volcanic edifice in the central part, a lava plateau in the eastern part, and multiple cinder cones spread throughout the island ([PERSON] et al., 2005) [6]. A low-velocity layer (LVL) beneath the extrusive volcanic outcrops from the Quaternary age with depths of 100-200 m was identified using HVSR inversion by [PERSON] and [PERSON] (2012) [7]. [PERSON] et al. (2007) also found that the LVL relates to the Pleistocene marine sediments of the Seoguipo and U formations, which in turn correspond to geological units specific to Jeju Island [8]. Seismic design characteristics are usually expressed as design response spectra, which include local/regional seismotectonic characteristics and seismic wave attenuations. In recent years, performance-based seismic design response spectra, which consider seismic performance based on the type and importance of the building structure, have been introduced and are an active area of research ([PERSON], et al., 2012, Regulatory Guide 1.208, 2007) [9; 10]. The KBC 2016 for general structures and buildings was revised in 2016, replacing KBC 2009. However, owing to the lack of studies on the seismotectonic characteristics of the Korean Peninsula, the suitability of the seismic design code is uncertain [9; 10]. Researchers conducted studies on seismic response spectra and applied their work to seismic engineering. Furthermore, [PERSON] (1959) developed seismic design spectra using eight horizontal ground motions that were recorded during four strong earthquakes [11]. Many others have researched the response spectra. [PERSON] and [PERSON] (2004) and [PERSON] (2004) stated that the vertical and horizontal response spectra are significantly influenced by factors such as resonance frequency, epicentral distance, soil type, earthquake magnitude, and fault movement [12; 13]. [PERSON] and [PERSON] (2016), [PERSON] et al. (2016), [PERSON] et al. (2016), [PERSON] et al. (2018), [PERSON] et al. (2018), [PERSON] et al. (2018), and [PERSON] et al. (2019) studied the response spectra for inland seismic stations based on the Fukuoka, Gyeongju, and Pohang earthquake series [1; 2; 4; 14; 15; 16]. Therefore, the verification of seismic design standards for the Jeju area is of particular interest owing to the few recent occurrences of macro earthquakes larger than ML-4.0.