Vertical movements of the Murono mud volcano in Japan caused by the Naganoken Kamishiro Fault Earthquake in 2014

Abstract

We observed vertical movements of the Murono mud volcano, Niigata, Japan, caused by the Naganoken Kamishiro Fault Earthquake (M = 6.7) on 22 November 2014. Precise levelling around the mud volcano was carried out on 27 November 2014, and the obtained elevation was compared with the data obtained for 11 November 2014. It was found that an elliptical uplift area, about 46 mm in magnitude and an order of magnitude smaller than that of the ones formed due to the past movements caused by the earthquakes in the same area, had been formed. It was considered that the structures of the shallow subsurface as well as the distance between the mud volcano and epicentre might play an important role in understanding the magnitude of vertical movements and distribution patterns.

Seismic and inter-seismic ground surface deformations of the Murono mud volcano (central Japan): a laser scanning approach

“…This suggests that the 2014 earthquake likely affected the spatial pattern, including both uplift and subsidence. The maximum uplift (30 mm) in this period roughly corresponds to that derived from a leveling survey (46 mm, Kusumoto et al 2015) but is less than that observed in period I. This may be attributed to the relatively low acceleration experienced in the area (0.22 cm/s 2 ) in the 2014 earthquake (Table 2).…”

“…1c). The western side of the site is partially deformed, while the center of the site, which contains a vent, does not show obvious uplift (Kusumoto et al 2014(Kusumoto et al , 2015. In contrast, the eastern side has particularly large and frequent deformations.…”

“…Although Kusumoto et al (2015) pointed out that the uplift area was elliptical with major and minor axes of about 80 and 40 m, respectively, the conspicuous, essential uplift area is narrower. In previous studies, the conspicuous uplift areas were reported in the same location, and they have a common size with major and minor axes of about 40 and 30 m, respectively.…”

“…The North Nagano Prefecture Earthquake (M w = 6.4, epicenter 16 km away, maximum acceleration of 3.08 cm/s 2 ) in March 2011 and the Nagano-ken Kamishiro Fault Earthquake (M w = 6.7, epicenter 76 km away, maximum acceleration of 0.22 cm/s 2 ) in November 2014 also caused remarkable vertical deformations of greater than 200 mm (revealed by laser scanning) and 46 mm (by leveling survey), respectively (Matta et al 2012;Kusumoto et al 2015; National Research Institute for Earth Science and Disaster Resilience 2016). Vertical deformation continues even in the interseismic period with seasonal variations of about ±5 mm, revealed by leveling surveys (Kusumoto et al 2014).…”

“…For large mud volcanoes (on the scale of hundreds of meters to kilometers), surface deformation can be detected by long-range remote sensing techniques, including satellite interferometric synthetic aperture radar (InSAR) (Mellors et al 2007;Fukushima et al 2009;Antonielli et al 2014), aerial photographs (Shakirov et al 2004;Istadi et al 2009), and airborne laser scanning (ALS) (Doshida et al 2007). Detection of surface deformation of small mud volcanoes (smaller than hundreds of meters) requires finer measurements that may include leveling, total station, and the use of high-precision global navigation satellite system (GNSS) (e.g., Onishi et al 2009;Kusumoto et al 2014Kusumoto et al , 2015. Even these approaches are often limited in their ability to reveal the spatial variation of surface deformation because of the low spatial density of their measurement points.…”