Shallow magma chamber under the Wudalianchi Volcanic Field unveiled by seismic imaging with dense array

Abstract

The Wudalianchi Volcano Field (WDF) is a typical intraplate volcano in northeast China with generation mechanism not yet well understood. As its last eruption was around 300 years ago, the present risk for volcano eruption is of particular public interest. We have carried out a high‐resolution ambient noise tomography to investigate the location of magma chambers beneath the volcanic cones with a dense seismic array of 43 seismometers and ~ 6 km spatial interval. Significant low‐velocity anomalies up to 10% are found at 7–13 km depth under the Weishan volcano, consistent with the pronounced high electrical‐conductivity anomalies from previous magnetotelluric survey. We propose these extremely low velocity anomalies can be interpreted as partial melting in a shallow magma chamber with volume at least 200 km3 which may be responsible for most of the recent volcanic eruptions in WDF. Therefore, this magma chamber may pose a serious hazard for northeast China.

Antarctic ice-sheet structures retrieved from P-wave coda autocorrelation method and comparisons with two other single-station passive seismic methods

“…This method was extended to a 1-D elastic medium by Frasier (1970) and later to a 3-D elastic medium by Wapenaar and others (2004). Unlike cross-correlations conducted to retrieve Green's function between station pairs, and often used to extract the surface-wave component (Campillo and Paul, 2003; Shapiro and Campillo, 2004; Li and others, 2016), the autocorrelation method can retrieve body-wave reflection responses of discontinuities at different depths by assuming a co-located source and receiver at a single station. Compared with the PRF method that exploits a deconvolution algorithm between radial (or tangential) and vertical components, and the HVSR method that divides vertical and horizontal amplitude spectra, the autocorrelation method uses only one component employing the correlation algorithm.…”

Supplemental Material: Magma recharging beneath the Weishan volcano of the intraplate Wudalianchi volcanic field, northeast China, implied from 3-D magnetotelluric imaging

“…In addition, we also assembled continuous data recorded by 15 temporary seismic stations from dense array around the WS volcano of Li et al (2016). We detected 7 seismic events around the WS volcano ( Figure S13a), among which some clearly show the characteristic volcanic tremor signals ( Figure S13d-h).…”

“…Figure S13. Distribution of selected seismic stations of temporary seismic array around the WS volcano ofLi et al (2016) and detected events, as well as their waveforms.…”

Volcanogenic CO2 Degassing in the Songliao Continental Rift System, NE China

“…Seismic tomography studies have shown the presence of a magma reservoir under the Weishan volcano in WMVF (Figures 1(b) and 1(c)), which is considered as evidence for partial melting in a shallow magma chamber at 7~13 km depth [33]. Surface manifestation of such activity is mainly expressed as cold-mineral bubbling springs with high p CO2 and low water temperature (generally between 4 and 7°C), prevalently distributed on the flanks or at the margin of the active volcanic cones (Figure 1(c)) [18,21], and located roughly at the same elevation (about 300 to 320 m.a.s.l., Figure 1…”