The Design Goals of PANDA , PANDA Ⅱ , and PANDA Ⅲ Seismic Arrays and Their Applications to Regional Seismic Network Monitoring

(Jer Ming Chiu),(Greg Steiner) 한국지진연구소 1996 MODERN SEISMOLOGY Vol.- No.-

Estimation of Regional Seismic Hazard in the Korean Peninsula Using Historical Earthquake Data between A.D. 2 and 1995

Jer Ming Chiu,So Gu Kim 한국지진연구소 2004 김소구 개인논문 Vol.3 No.-

Located between the very active Japan and Ryukyu subduction zones and the northern China plate, the Korea Peninsula has been considered a part of the stable Eurasia continent and is very quiet in seismic and tectonic activity. Although there were many significant damaging earthquakes reported in historical times, seismic hazard in Korea has long been overlooked. Modern earthquake activity in the Korean Peninsula is very low and is not well recorded, at least until 1998 when the modernization of the Korean National Seismic Network was implemented. Thus, modern earthquake data are not adequate for evaluating seismic hazard in the Korean Peninsula. On the other hand, the historical earthquake catalog, which includes documented earthquake information from around the Korean Peninsula and can be dated back to as early as A.D. 2, provides the only available long-term database for the investigation of temporal and spatial patterns of earthquake activity. The importance of seismic hazard assessment has significantly increased in modern times because of the precent construction of many critical facilities, such as nuclear power plants, supercomputer centers, large hospitals, and high-technology centers, throughout the entire Korean Peninsula. Although uncertainties on the historical earthquake locations and their magnitudes are expected to be large, information obtained from this historical earthquake catalog can ta least provide a long-term scientific basis for an estimation of seismic hazard in Korea. For the entire Korean Peninsula, seismic hazard is evaluated in terms of the spatial distribution of seismicity and relative seismic energy release over the 2000 years of the historical record. Results from our preliminary analysis clearly demoinstratc that seismic activity in the Korean Peninsula can be categorized into four prominent seismic zones, inside which seismic hazard is much higher than that in the surrounding regions. These four seismic zones include: (1) the western Korean seismic zone extending from Seoul to Pyongyang, which is characterized by a few concentrated regions of high seismicity and a high relative seismic energy release; (2) the eastern Korean seismic zone, which is characterized by a low seismic rate but a high relative seismic energy release from a few large historical events; (3) the northeastern Korean seismic zone, which is probably related to the deep Japan subduction-zone earthquake underneath northeast China and has a very low seismicity but a very high relative energy release; and (4) the southern Korean seismic zone, which is characterized by many scattered patches of high seismicity and a few zones of high seismicity and relative seismic energy release from a few large historical events. Among the three most seismically active regions near Pyongyang, Soeul, and Pusan, the probability of occurrence for and earthquake of magnitude grearter than 5.0 is estimated to be about 1%, 2% and 3% per year, respectively. Since significant damaging earthquakes (M>-7.0) have occurred in these three regions in historical times, an effective assessment of seismic hazard potential in the Pyongyang, Seoul, and Pusan regions cannot be overlooked.

The Empirical Seismic Risk Mapping in the Korean Peninsula Based on Earthquake data between 2 A.D. and 1995

Kim, So Gu,Chiu, Jer-Ming 한국지진연구소 1997 SAFE Vol.3 No.1

Located between the very active Japan and Rrykyu subduction zones and the northern China plate, the Korean Peninsula tab been considered by many researchers very quiet in seismic and tectotic activities. Modern earthquake activity in the Korean Peninsula is very low and not well-recorded that it is not adequate for the evaluation of seismic hazard problem in the Korean Peninsula. On the other hand, historical earthquake catalog which includes documented earthquake information around the Korean Peninsula dated back to as early as 2 A.D. provides the only available long-term database for the investigation of temporal and spatial patterns of earthquake activities to assess the significance of earthquake risk problems in the region. Although, uncertainties on the historical earthquake location and its magnitudes are expected to be very large, information obtained from this historical earthquake catalog will provide a conservative estimation of seismic risk in Korea. We have estimated the spatial distributions of seismicity and seismic energy released over the 2000 years of historical time in a relative scale to evaluate seismic risk for the entire Korean Peninsula. Results from our preliminary analysis have clearly demonstrated that seismic activities in the Korea Peninsula can be categorized into four prominent seismic zones inside which seismic risk is much higher than that in the surrounding regions. These four seismic zones include (1) western Korean seismic zone extending from Seoul to Pyongyang is characterized by a few concentrated regions of high seismicity and high seismic energy released, (2) eastern Korean seismic zone is characterized by a low rate of seismicity but high seismic energy released, (3) the northeastern Korean seismic zone is most probably related to the deep subduction zone earthquakes that ig low seismic rate but high energy released, and (4) the southern Korean seismic zone is characterized by many scattered patches of seismicity and a few zones of high seismicity and high seismic energy released, Among the three highest seismicity regions including the regions south of Pyongyang, northwest of Seoul and north of Pusan, the probabilities of an earthquake of magnitude greater than 4.0 to occur is about 6%, 4%, and 3% per year, respectively, and for an earthquake of magnitude greater than 5.0 is about 1%, 2%, and 3% per year, respectively.

Poster Session : PS 0059 ; Cardiology : Lymphoma with Constrictive Pericarditis

( Zhen Yu Liao ),( Jer Young Liou ),( Kou Gi Shyu ),( Huey Ming Lo ),( Jun Jack Cheng ),( Chiung Zuan Chiu ) 대한내과학회 2014 대한내과학회 추계학술발표논문집 Vol.2014 No.1

Patients with pericardial diseases usually present with nonspecifi c symptoms, these diseases may not be detected until they have reached an advanced stage. It is therefore important to distinguish between normal pericardial structure and disease. Pericardial constriction is typically chronic, but variants include subacute, transient, and occult constriction. Pathologically, this results in chronic infl ammation and, frequently, calcifi cation. Constrictive pericarditis has multiple etiologies and can lead to disablingsymptoms and severe heart failure with poor quality of life. We described a patient who presented with symptoms of heart failure and was found to have diastolic heart failure. Several investigations pointed to the diagnosis of constrictive pericarditis which was later confi rmed by cardiac catheterisation. The etiology turns out to be primary cardiac lymphoma which is extremely rare in immunocompetent patients.

Relocation of Earthquakes in the New Madrid Seismic Zone: Estimation of 1D Velocity Structure and Geometry of a Seismogenic Fault

Park, Junghyun,Lee, Jung Mo,Chiu, Jer‐,Ming,Kim, Woohan,Kim, Won‐,Young Seismological Society of America 2015 Bulletin of the Seismological Society of America Vol.105 No.2

<P>Determination of reliable hypocenters of earthquakes is crucial to earthquake seismology and to evaluate hazards associated with earthquakes. There are many associated computer codes for this purpose; however, most of the location algorithms are designed to determine hypocentral parameters based on previously determined velocity models. In contrast, we employed a location method that is independent of the initial velocity model, using a genetic algorithm (GA) to determine an optimal 1D velocity model and the locations of earthquakes. Using this GA, we relocated earthquakes that occurred in the New Madrid Seismic Zone (NMSZ) in the central United States between October 1989 and August 1992. The goal of this work was to delineate the possible fault planes by reliable relocation of those earthquakes and to determine a 1D velocity structure for the NMSZ. A total of 502 earthquakes recorded by 37 Portable Array for Numerical Data Acquisition (PANDA) stations were used in the relocation study. In the relocation process, the root mean square travel‐time residuals were reduced by ∼35%, corresponding to an average of 2.3 km deeper in depth, 0.7 km shift in latitude, and 0.8 km shift in longitude compared with those in the initial catalog locations. The hypocenters of the earthquakes can be subdivided into four groups based on their spatial distributions. The group that corresponds to the Cottonwood Grove fault (CGF) in the southwestern NMSZ represents a very steep plane, whereas the other three groups fall into Reelfoot fault (RF). We inverted <I>P</I>‐ and <I>S</I>‐wave travel times from the new hypocentral parameters to determine 1D velocity models. The resulting eight‐layered velocity models consist of a 2 km thick surface layer followed by seven 2 km thick layers, with <I>V</I><SUB><I>P</I></SUB> ranges from 5.36 to 6.74  km/s and <I>V</I><SUB><I>S</I></SUB> ranges from 2.83 to 3.90  km/s for both CGF and RF regions.</P><P><I>Online Material: </I>Interactive visualizations of hypocentral distributions.</P>