Shallow seismic reflection profiling across the western marginal faults of Kitakami Lowland, northern Honshu Island, Japan

In 1997-1998, integrated passive and active seismic experiments were conducted in northern Honshu, Japan. These experiments aimed at understanding the relationship between earthquake occurrence and deformation process of the intra-island-arc crust. In the summer of 1998, a shallow seismic reflection survey was conducted to obtain the fault’s detailed geometry to depths of 1km across the western marginal faults of Kitakami Lowland, Iwate Pref., Japan. The seismic source was a mini-vibrator. The data set recorded by the digital telemetry system was processed using seismic reflection technique. Imaging was preformed using conventional common mid-point processing steps, including post-stack migration and depth conversion. A reflection image shows the deep geometry of the Uwandaira fault, which is positioned at the eastern edge of the Ou Backbone range

High-resolution seismic reflection profiling across the Shiraiwa fault, eastern margin of the Yokote basin fault zone, northeast Japan : data acquisition and processing

The eastern margin of the Yokote basin fault zone extends about 56km at the western foot of the Ou Backbone Range, northeast Japan. The Rikuu earthquake (M=7.2) occurred in the Ou Backbone Range (Mahiru Range) on 31st August, 1896. Associated with this earthquake, four thrust faults-Obonai, Shiraiwa, Ota, and Senya fault3 appeared on the surface of the western foot of the Mahiru Range. These faults were highly sinuous with numerous gaps and en echelon steps. We conducted a high-resolution seismic reflection profiling survey across the Shiraiwa fault. The obtained seismic reflection data were processed by conventional common mid-point methods, post-stack migration, and depth conversion. The subsurface structure across the Shraiwa fault is characterized by branched low-angle reverse faults and conjugate back-thrust. The emergent thrust associated with the 1896 earthquake is regarded to be a subsidiary reverse fault

High-resolution seismic reflection profiling across the Senya fault at Hanaoka, northern Honshu, Japan: Data acquisition and processing

The Senya fault, northern Honshu, Japan, which generated the Rikuu earthquake (Mj 7.2) 1896, is a typical intra-arc active thrust. Subsurface geometry provides essential information for better understanding strong ground motions and crustal deformation processes. A high-resolution seismic reflection survey was conducted along the 63km long seismic line across the toe of the thrust to reveal the subsurface geometry. The seismic source was a Mini-vibrator truck and the receiver interval was 10 m. The seismic data were processed by the standard common mid-point method. The Senya fault is clearly identified as a boundary between horizontal reflectors of the basin fill in the Yokote basin and moderately dipping reflectors beneath the Senya hills. The thrust occurred in late Miocene mudstone, and shows a flat and ramp geometry. The emergent thrust dips 30 degrees down to 500m, and changes its dip to subhorizontal following the distribution of the mudstone

Crustal structure off the northwestern Sado Island in the eastern margin of the Japan Sea deduced from seismic refraction and reflection surveys

http://www.godac.jamstec.go.jp/darwin/cruise/kaiyo/ky09-06/

屈折法・広角反射法探査による佐渡島北西沖竏註ｼ会津地域の地殻・最上部マントル構造

http://www.godac.jamstec.go.jp/darwin/cruise/kaiyo/ky09-06/

日本海佐渡島沖・東北日本弧―西南日本弧境界域の地震学的構造特徴

http://www.godac.jamstec.go.jp/darwin/cruise/kaiyo/ky09-06/ehttp://www.godac.jamstec.go.jp/darwin/cruise/kairei/kr14-08/

High-Resolution Seismic Reflection Profiling Across the Western Marginal Faults of the Kitakami Lowland in Hanamaki Area, Eastern Margin of Ou Back-bone Range, Northeast Honshu, Japan

The western marginal faults of the Kitakami Lowland are active faults along the eastern rim of the Ou Back-bone Range, northeast Honshu, Japan. To reveal the relationship between geomorphic and geological structures, high-resolution seismic reflection profiling was performed across the faults. The seismic source was a mini-vibrator, and seismic data were obtained by a digital telemetry system. Source and receiver intervals are 20m and 10m, respectively. The resultant depth-converted seismic section shows the flexural structure of the uppermost Miocene to middle Pleistocene strata above the faults and the youngest strata overlying the structure with oblique unconformity

P- and S-Wave Seismic Reflection Profiling Across the Kamishiro Fault, Itoigawa-Shizuoka Tectonic Line Active Fault System, Central Japan

The Kamishiro fault forms the northern-most part of the Itoigawa-Shizuoka Tectonic Line (ISTL) active fault system. This fault displaced young lake deposits in the Kamishiro basin, and the shallow (less than 20m) structure of the fault and an average long-term vertical slip rate of 2.2－2.7m/kyr were revealed by drilling and geomorphological investigations. To reveal the subsurface structure of this fault system and estimate long-term net slip rate, we carried out S- and P-wave high-resolution shallow seismic reflection profiling across the Kamishiro fault. The S-wave seismic line is 200m, the receiver point intervals are 1m, and the shot point intervals are 2m. We used a 192-channel seismic system with a mini-vibrator to image the depth range of 5 to 70m. The P-wave seismic line is 2.1km, the receiver point intervals are 10m, and the shot point intervals are 10m. We used a 176-channel seismic system with a mini-vibrator to image the depth range of 50 to 800m. From these experiments, it is clarified that the Kamishiro fault cut and fold the lacustrine deposit. The deformation is associated with fault development near the surface. Given the dip angle of the Kamishiro fault determined by S-wave seismic profiling to be approximately 30°, the average dip slip-rate is calculated to be 4.4-5.4m/kyr. And, the Kamishiro fault corresponds to cutting across the anticline rather than the deformation front on the P-wave seismic profile. The fold is related to blind thrust fault, fold propagation fold, or drag structure

Long-term safety and efficacy of alogliptin, a DPP-4 inhibitor, in patients with type 2 diabetes: a 3-year prospective, controlled, observational study (J-BRAND Registry)

Introduction Given an increasing use of dipeptidyl peptidase-4 (DPP-4) inhibitors to treat patients with type 2 diabetes mellitus in the real-world setting, we conducted a prospective observational study (Japan-based Clinical Research Network for Diabetes Registry: J-BRAND Registry) to elucidate the safety and efficacy profile of long-term usage of alogliptin.Research design and methods We registered 5969 patients from April 2012 through September 2014, who started receiving alogliptin (group A) or other classes of oral hypoglycemic agents (OHAs; group B), and were followed for 3 years at 239 sites nationwide. Safety was the primary outcome. Symptomatic hypoglycemia, pancreatitis, skin disorders of non-extrinsic origin, severe infections, and cancer were collected as major adverse events (AEs). Efficacy assessment was the secondary outcome and included changes in hemoglobin A1c (HbA1c), fasting blood glucose, fasting insulin and urinary albumin.Results Of the registered, 5150 (group A: 3395 and group B: 1755) and 5096 (3358 and 1738) were included for safety and efficacy analysis, respectively. Group A patients mostly (>90%) continued to use alogliptin. In group B, biguanides were the primary agents, while DPP-4 inhibitors were added in up to ~36% of patients. The overall incidence of AEs was similar between the two groups (42.7% vs 42.2%). Kaplan-Meier analysis revealed the incidence of cancer was significantly higher in group A than in group B (7.4% vs 4.8%, p=0.040), while no significant incidence difference was observed in the individual cancer. Multivariate Cox regression analysis revealed that the imbalanced patient distribution (more elderly patients in group A than in group B), but not alogliptin usage per se, contributed to cancer development. The incidence of other major AE categories was with no between-group difference. Between-group difference was not detected, either, in the incidence of microvascular and macrovascular complications. HbA1c and fasting glucose decreased significantly at the 0.5-year visit and nearly plateaued thereafter in both groups.Conclusions Alogliptin as a representative of DPP-4 inhibitors was safe and durably efficacious when used alone or with other OHAs for patients with type 2 diabetes in the real world setting