Fig. 4

Radial- and transverse-deconvolved waveforms (RDWs and TDWs) for D/V Chikyu airgun and ship noise. a RDWs for D/V Chikyu airgun (left) with 20 shots and ship noise (right) during Julian days 1–58 at OBS03. The days without data (gray shaded areas) correspond to the drilling period, and quiet data after day 59 correspond to the period when D/V Chikyu moved to other sites. Arrows represent coherent signals that can be observed in both the RDWs. b Same as panel a, but for TDWs. c (top) Waveforms stacked over (black) 20 shots and (red) 58 days in panel a. (bottom) Cross-correlation coefficients between the red and black waveforms in the top panel, with a time window of 0.1 s and a time shift of 0.05 s. d Same as c, but for panel b. e Same as panel a, but for OBS02. f Same as panel a, but for OBS05