Seismogenesis at Hikurangi Integrated Research Experiment (SHIRE) offshore data

This is the offshore dataset of a large onshore-offshore seismic experiment on the Hikurangi margin of North Island, New Zealand, with a team of scientists from New Zealand, the United States, and Japan. This data acquisition was part of the SHIRE project (“Seismogenesis at Hikurangi Integrated Research Experiment”) and occurred in 2017. The goals of this Earth science project were: 1) to obtain constraints on the deep structure of the Hikurangi margin, with an emphasis on Raukumara peninsula in the north, and 2) to record seismicity over several months. During the marine seismic experiment, we used the acoustic source and streamer of the US academic research vessel R/V Marcus Langseth (voyage MGL1708) to gather marine seismic reflection and refraction data. The R/V Tangaroa took part in a voyage undertaking OBS operations in cooperation with this, deploying and recovering a fleet of 100 short-period ocean-bottom seismometers (OBSs) from the Japan Agency for Marine-Earth Science and Technology (JAMSTEC). Voyage TAN1710’s deployed and recovered OBSs at 114 sites along four major lines. SHIRE Line 1 is oriented NW–SE between the Bay of Plenty and the northern Hikurangi Trough. Land seismometers on the Raukumara peninsula section of this transect recorded the Langseth source as well. SHIRE Line 2 is a margin-crossing transect on the southern Hikurangi margin, while Line 3 and Line 4 are two margin-parallel lines on the continental shelf and on the Hikurangi Plateau, respectively. After the R/V Marcus Langseth started surveying these geophysical transects, 21 of the instruments from Lines 1 and 3 were repositioned on SHIRE Line 4.