Undersea co-seismic crustal movements associated with the 2005 Off Miyagi Prefecture Earthquake detected by GPS/acoustic seafloor geodetic observation

Matsumoto, Yoshihiro; Fujita, Masayuki; Ishikawa, Tadashi; Mochizuki, Masahito; Yabuki, Tetsuichiro; Asada, Akira

doi:10.1186/bf03352663

Cited by 32 publications

(19 citation statements)

References 7 publications

(10 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[11] The whole time series in Figure 3 can be specified as three phases of different features. The first phase is the co-seismic phase right at the event, showing an eastward co-seismic movement of about 10 cm, already reported by Matsumoto et al [2006]. A closer look at the time series after the event leads us to observe that they can be further divided into two phases at around the end of 2006 in view of the difference in the trend.…”

Section: Observation Results At Seafloor Reference Point Mygwsupporting

confidence: 65%

“…At MYGI, located about 100 km landward from the axis of the Japan Trench, the intraplate movement toward WNW was found through our first couple of years observations [ Fujita et al , 2006]. In association with the 2005 Off‐Miyagi Prefecture earthquake, an eastward co‐seismic movement of about 10 cm was detected at MYGW, located about 10 km east of the epicenter, while no prominent movement was found at MYGI, about 50 km further east of MYGW [ Matsumoto et al , 2006].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Restoration of interplate locking after the 2005 Off-Miyagi Prefecture earthquake, detected by GPS/acoustic seafloor geodetic observation

Sato

Saito

Ishikawa

et al. 2011

Geophys. Res. Lett.

Self Cite

View full text Add to dashboard Cite

A 7.2‐magnitude earthquake occurred on the plate boundary off Miyagi Prefecture, northeastern Japan, on 16 August 2005. From seafloor geodetic observations using the GPS/acoustic combination technique in this area, we have detected notable seafloor movements associated with, and subsequent to this event. The time series of horizontal coordinates obtained at the seafloor reference point MYGW, located about 10 km east of the epicenter, indicates that the strain accumulated for the interseismic period was partly released by the event and a constant strain accumulation restarted after 1–2 years of the post‐seismic period with an erratic movement. The horizontal velocity of MYGW after the restart above is estimated to be about 5.7 cm/year toward WNW relative to the Eurasian plate. Our result is consistent with those derived from terrestrial GPS measurements and implies that the interplate locking was restored in the rupture area of the 2005 event around 2007.

show abstract

Section: Observation Results At Seafloor Reference Point Mygwsupporting

confidence: 65%

Section: Introductionmentioning

confidence: 99%

Restoration of interplate locking after the 2005 Off-Miyagi Prefecture earthquake, detected by GPS/acoustic seafloor geodetic observation

Sato

Saito

Ishikawa

et al. 2011

Geophys. Res. Lett.

Self Cite

View full text Add to dashboard Cite

show abstract

“…In Japan, our group first succeeded in detecting seafloor movements caused by interseismic plate convergence at the Japan Trench ) and has continued to monitor the movements including coseismic and postseismic deformation at the seafloor sites along the Japan Trench (e.g., Matsumoto et al 2006;Sato et al 2011a, b;Sato et al 2013b;Watanabe et al 2014) and the Nankai Trough (e.g., Yokota et al 2015). Moreover, other groups in Japan have provided important results (Kido et al 2006;Kido et al 2011;Tadokoro et al 2012;Yasuda et al 2014) to understand the major interplate earthquakes as well.…”

Section: Methods and Observation Datamentioning

confidence: 99%

Non-volcanic crustal movements of the northernmost Philippine Sea plate detected by the GPS-acoustic seafloor positioning

2015

Self Cite

View full text Add to dashboard Cite

Repeatedly performing the GPS-acoustic seafloor positioning, we first succeeded in detecting non-volcanic seafloor movements on the Philippine Sea plate (PHS) subducting along the Sagami Trough. At a seafloor geodetic site on the northernmost part of the PHS off the Boso Peninsula, we detected significant eastward motion with respect to the central part of the PHS. This is unaccountable by the coupling between the Pacific plate and the PHS along the Izu-Bonin (Ogasawara) Trench because it would cause the westward elastic deformation at BOSS. It is rather consistent with the rigid motion of the tectonic block in the fore-arc along the Izu-Bonin Trench, associated with the back-arc rift. The other site on the western side of the Sagami Bay had moved toward the north relative to the Izu Peninsula. It suggests that the Izu microplate obviously moves relative to the northern PHS. The difference between the velocities of the Sagami Bay and the Izu Peninsula indicates the coupling on the boundary fault as well.

show abstract

“…Our past observations near the Japan Trench provided great advantage in understanding the 2005 Off-Miyagi Prefecture earthquake (M7.2) (e.g., Matsumoto et al 2006 andSato et al 2011b), the 2011 Tohoku-oki earthquake (M9.0) (e.g., Sato et al 2011a andSato et al 2013b), and others. Important observations have also been made by other research groups in Japan such as Tohoku University (e.g., Kido et al 2006 andKido et al 2011) and Nagoya University (e.g., Tadokoro et al 2012 andYasuda et al 2014).…”

Section: Seafloor Geodetic Observation Using a Gps-acoustic Combinatimentioning

confidence: 99%

Heterogeneous interplate coupling along the Nankai Trough, Japan, detected by GPS-acoustic seafloor geodetic observation

Yokota

Ishikawa

Sato

et al. 2015

Prog. in Earth and Planet. Sci.

Self Cite

View full text Add to dashboard Cite

The recurring devastating earthquake that occurs in the Nankai Trough subduction zone between the Philippine Sea plate and the Eurasian plate has the potential to cause an extremely dangerous natural disaster in the foreseeable future. Many previous studies have assumed interplate-coupling ratios for this region along the trench axis using onshore geodetic data in order to understand this recursive event. However, the offshore region that has the potential to drive a devastating tsunami cannot be resolved sufficiently because the observation network is biased to the land area. Therefore, the Hydrographic and Oceanographic Department of Japan constructed a geodetic observation network on the seafloor along the Nankai Trough using a GPS-acoustic combination technique and has used it to observe seafloor crustal movements directly above the Nankai Trough subduction zone. We have set six seafloor sites and cumulated enough data to determine the displacement rate from 2006 to January 2011. Our seafloor geodetic observations at these sites revealed a heterogeneous interplate coupling that has three particular features. The fast displacement rates observed in the easternmost area indicate strong interplate coupling (>75%) around not only the future Tokai earthquake source region but also the Paleo-Zenisu ridge. The slow displacement rates near the trench axis in the Kumano-nada Sea, a shallow part of the 1944 Tonankai earthquake source region, show a lower coupling ratio (50% to 75%). The slow displacement rate observed in the area shallower than the 1946 Nankaido earthquake source region off Cape Muroto-zaki reflects weakening interplate coupling (about 50%) probably due to a subducting seamount. Our observations above the subducting ridge and seamount indicate that the effect of a subducting seamount on an interplate-coupling region depends on various conditions such as the geometry of the seamount and the friction parameters on the plate boundary.

show abstract

Undersea co-seismic crustal movements associated with the 2005 Off Miyagi Prefecture Earthquake detected by GPS/acoustic seafloor geodetic observation

Cited by 32 publications

References 7 publications

Restoration of interplate locking after the 2005 Off-Miyagi Prefecture earthquake, detected by GPS/acoustic seafloor geodetic observation

Restoration of interplate locking after the 2005 Off-Miyagi Prefecture earthquake, detected by GPS/acoustic seafloor geodetic observation

Non-volcanic crustal movements of the northernmost Philippine Sea plate detected by the GPS-acoustic seafloor positioning

Heterogeneous interplate coupling along the Nankai Trough, Japan, detected by GPS-acoustic seafloor geodetic observation

Contact Info

Product

Resources

About