• Journal of the Korean earth science society
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• v.39 no.4
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• pp.342-348
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• 2018

An earthquake of $M_L$ 5.8 hit the Gyeongju area on September 12, 2016. A sequence of foreshock-mainshock-aftershock of 588 events with equal to or greater than magnitude 1.5 occurred for six months in this area. Around ninety-nine percentage (98.8%) of the total energy was released intensively within a day, and about 80% of the total events took place within a month after the Gyeongju earthquake. The epicentral distribution of aftershocks of major events ($M_L$ 5.1, 5.8, 4.5, and 3.5) were elongated in the direction of $N30^{\circ}E$. They correlate well with the focal mechanism solution. These facts support the inference that the Gyeongju earthquakes occurred on a sub-parallel subsidiary fault of the Yangsan fault zone or on the linking damage zones between Deokcheon and Yangsan fault. During the last six years before the Gyeongju earthquake, there were few events within 10-km radius from the epicenter. This seismic gap area was filled with a sequence of the Gyeongju earthquakes. The b value for aftershock of the Gyeongju earthquakes is 1.09.

• Journal of The Geomorphological Association of Korea
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• v.25 no.1
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• pp.19-30
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• 2018

This study tries to infer fault lines and produce a map for the lines based on a classification of fault-related landforms and fluvial landformsin the Gyeongju area of the Yangsan Fault Valley. Fault activities in the study area are thought to be older than the time of river formation or stronger than the erosion by river, while the northern and southern parts of the study area seem to have experienced fault activities after valley formation. It is also possible that weaker fault activities than the erosion by river seem to have been prevailed in the parts. In the study area, the Gyeongju alluvial fan is located within a wide erosional valley at the joint area of the Yangsan and Ulsan Faults. From the distribution of the landforms, it is inferred that several fault lines parallel to the Yangsan Fault are distributed at both sides of the fault valley. In particular, the area from Bae-dong to Nogok-ri, Naenam-myeon shows the most obvious linearity of the landforms within the study area. Several fault lines with a direction of NNE-SSW are also found around the epicenter of the 2016 Gyeongju Earthquake.

• Journal of the Korean housing association
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• v.18 no.5
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• pp.93-102
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• 2007

The purpose of this study is to explore the changes in space structure in urban residential areas, based on the historical and cultural background of Gyeongju area. In order to clarify its residential and cultural properties, the residential patterns and living characteristics identifying its historical context were analysed. This study was carried out with the data of the Hwango-dong area that has maintained its original form since the creation as a urban residential area during the 1960s and 1970s, the data of the Dongbang village area that was developed as one of residential area projects during the 1970s, and the data of the Seonggeon-dong area that was developed as a residential area during the 1970s and 1980s. The analyses on previous studies and statistical data, referring to building administration registers, field survey and photographing of house types, and exploration of living characteristics by house types were used to perform this study. Four hundred and five sample houses were used in this study, having forty one sample houses which were used for living survey and actual plane measurement. The result of this study can be used as basic information for designing the house to meet Gyeongju citizens' desire for living environments, and to maintain the cultural and historical contexts.

• East Asian mathematical journal
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• v.30 no.5
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• pp.583-597
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• 2014

In this paper, we study an area-preserving piecewise linear map with the feature of dangerous border collision bifurcations. Using this map, we study dynamical properties occurred in the invariant set, specially related to the boundary of KAM-tori, and the existence and stabilities of periodic orbits. The result shows that elliptic regions having periodic orbits and chaotic region can be divided by smooth curve, which is an unexpected result occurred in area preserving smooth dynamical systems.

• Journal of the Korean Geographical Society
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• v.39 no.1
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• pp.56-69
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• 2004

We investigated the distribution and geomorphic development of alluvial fan in Gyeongju City including Cheonbuk area. According to a relative height to a river bed, alluvial fans of this area are divided into Higher surface, Middle surface, and Lower surface. As alluvial fans of Bulguk temple∼Ulsan bay area, the confluent fans in Cheonbuk and Gyeongju areas were formed by the Quaternary climatic change alternating glacial and interglacial stages, and the development of N-S and NW-SE fault lines. The Gyeongju alluvial fan, the largest in Korea, has been provided as the significant space for human activity since the prehistoric age. Bukcheon river formed the Gyeongju alluvial fan had not flowed over during the prehistoric and the ancient times. In contrast with general geomorphic characteristics, many springs in the Gyeongju alluvial fan are located in the middle part of the fan because ground water reaches to the surface. It is supposed that sedimental materials were not sufficiently piled up at lower reach of Bukcheon river due to the large deposits at upper and middle reach of the basin.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.3
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• pp.45-62
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• 2020

This study is to present the basic data for the conservation and management of natural resources of National Park by understanding the ecological characteristics of special protected areas located in Tohamsan District, Gyeongju National Park, South Korea. The numbers of vascular plants were summarized as 106 taxa including 47 families, 79 genera, 96 species, 1 subspecies, 7 varieties and 2 forms. For status by sites, there were 59, 50 and 55 taxa in A area(Pedicularis ishidoyana), B area(Millettia japonica) and C area(Cypripedium macranthos), respectively. In the dominant species, the tree layer was Quercus serrata(A area), Platycarya strobilacea and Pinus koraiensis(B area) and Fraxinus rhynchophylla(C area), the subtree layer was Carpinus cordata and Quercus serrata(A area), Pinus koraiensis and Castanea crenata(B area) and Fraxinus rhynchophylla(C area), the 1^st shrub layer was Toxicodendron trichocarpum and Rhododendron schlippenbachii(A area), Lindera erythrocarpa and Styrax japonicus(B area) and Fraxinus rhynchophylla and Lindera erythrocarpa(C area), 2^nd shrub layer was Styrax obassis and Lespedeza maximowiczii(A area), Lespedeza maximowiczii and Rhododendron mucronulatum(B area) and Lindera erythrocarpa(C area), the herbaceous layer was Athyrium yokoscense, Dryopteris chinensis, Dryopteris lacera and Lindera obtusiloba(A area), Athyrium yokoscense, Millettia japonica, Carex humilis Leyss. var. nana and Carex ciliato-marginata(B area) and Hydrangea macrophylla (Thunb.) Ser. subsp. serrata, Ajuga spectabilis and Oplismenus undulatifolius(C area).

• Geophysics and Geophysical Exploration
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• v.20 no.3
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• pp.185-192
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• 2017

A sequence of earthquakes with the main shock $M_L$ 5.8 occurred on September 12 2016 in the Gyeongju area. The main shock was the largest earthquakes in the southern part of the Korean peninsula since the instrumental seismic observation began in the peninsula in 1905 and clearly demonstrated that the Yangsan fault is seismically active. The mean focal depth of the foreshock, main shock, and aftershock of the Gyeongju earthquakes estimated by the crustal model of single layer of the Korean peninsula without the Conrad discontinuity turns out to be 12.9 km, which is 2.8 km lower than that estimated based on the IASP91 reference model with the Conrad discontinuity. The distribution of the historical and instrumental earthquakes in the Gyeongju area indicates that the Yangsan fault system comprising the main Yangsan fault and its subsidiary faults is a large fracture zone. The epicenters of the Gyeongju earthquakes show that a few faults of the Yangsan fault system are involved in the release of the strain energy accumulated in the area. That the major earthquakes of Gyeongju earthquakes occurred not on the surface but below 10 km depth suggests the necessity of the study of the distribution of deep active faults of the Yangsan fault system. The magnitude of maximum earthquake of the Gyeongju area estimated based on the earthquake data of the area turns out to be 7.3. The recurrence intervals of the earthquakes over magnitudes 5.0, 6.0 and 7.0 based on the earthquake data since 1978, which is the most complete data in the peninsula, are estimated as 80, 670, and 5,900 years, respectively. The September 2016 Gyeongju earthquakes are basically intraplate earthquakes not related to the Great East Japan earthquake of March 11 2011 which is interplate earthquake.

• 한국문화재보존과학회:학술대회논문집
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• 2007.10a
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• pp.19-22
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• 2007

• Journal of the Korean Society of Food Culture
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• v.21 no.6
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• pp.577-588
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• 2006

This study was performed by questionnaire to investigate current use of native local foods of adults in Gyeongju classified by age. The subjects were consisted of 421 citizens(217 males and 204 females) living in Gyeongju. The findings are summarized as follows: 'Institute' scored high as 30.6% in the main responsible body for the succession of local foods. The most emphasized points to popularize the local foods was to 'taste'(36.4%). a point to be considered to develop tourism product of the local foods was to 'development of recipes acceptable to the people of today'(24.6%). The recognition rate score of native local foods of Gyeonngju area was 'Hwangnamppang', 'Hanjeongsik', 'Ssambap', 'Haejangguk', 'Hoe(Gampo)', 'Memilmukmuchim', 'Gyodongbeopju', and 'Yugoa' in the order. On the other hand, the recognition rate score for 'Ssukgulrei', 'Borisudan', 'Dalraikkakdugi', 'Hwanggeumju', 'Baesuk', 'Gyeojachae', 'Gungjungjeongol' was very low. The preferred and intake native local foods of Gyeongju area was 'Hanjeongsik', 'Ssambap', 'Hoe(Gampo)', 'Haejangguk', 'memilmukmuchim' in that other. On the other hand, the preference for 'Ssukgulrei' 'Borisudan', 'Hwanggeumju', 'Baesuk' and 'Dalraikkakdugi' was very low.

• Korean journal of food and cookery science
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• v.24 no.4
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• pp.549-559
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• 2008

This study was performed by questionnaire to investigate viewpoints regarding menu excavation and development of native local foods of adults in the Gyeongju area, classified by gender and age. The subject population consisted of 253 citizens(108 males and 145 females) living in Gyeongju. The findings are summarized as follows: The residents highly desired the 'enrichment of service and clean hygiene of local food restaurants', 'active marketing', 'necessity of excavation and development at the present time', and 'development with regional unique characteristics' with regard to the development of the local food choices in Gyeongju, whereas they did not particularly desire 'excavation development of cooking that often is served at family event(birth, marriage, death etc..)', nor 'guidance and enlightenment for many citizens'. The most influential obstacle hindering the development of Gyeongju local food was 'administration support deficiency of connection group agency', followed by 'interest deficiency about local food of restaurant business managers and citizens, different taste of each restaurant', and 'tradition cooking itself is insufficient in Gyeongju'. The most reasonable development menu for native local foods of the Gyeongju area was 'mushroom & beef hot pot(beoseothanu-jeongol)', 'glutinous barley bread(chalborippang)', 'mushroom & bulgogi hot pot(beoseot-bulgogi-jeongol)', 'grilled beef(hanu-sutbul-gui)', and 'grilled minced beef ribs(hanu-tteok-galbi)' in that order. On the other hand, the excavation and development validity scores for 'black goat soup(heukyeomso-tang)', 'gulfweed soup(mojaban-guk)', and 'parboiled octopus(muneo-sukhoe)' were very low.