Funding is provided to allow scientists to participate in two JAMSTEC cruises to the Mariana arc in July and Sept-Oct. 2010. The projects that led to the approval of these cruises resulted from ongoing collaboration between US and Japanese geoscientists. Cruise 1 will explore and sample submarine arc volcanoes in the southern Marianas between Guam and Pagan. Eight days of ROV diving with Hyperdolphin 3K aboard the R/V Natsushima (Guam-Guam; July 9-19, 2010) and will revisit, examine and sample several submarine volcanoes (Tracey, W. Rota, NW Rota-1, E. Diamante, Zealandia Bank area). The investigators will also explore W. Sarigan (in the Zealandia bank area) and Daon volcanoes for the first time. Cruise 2 (Guam-Guam; Sept. 17-Oct 1, 2010) continues igneous basement examinations of the Mariana forearc E, S, and SW of Guam that were studied in 2006 and 2008. The R/V Yokosuka will be mothership for 8 Shinkai 6500 dives and four Deep-tow camera dives in the southern Mariana forearc. In order to achieve the two major objectives, the investigators will focus their work on three major target areas: Forearc southeast of Guam, Santa Rosa Bank and the SE Mariana Forearc Rift.
Broader Impacts: These cruises enhance international collaboration in the marine sciences. They also enhance collaboration between academic scientists and those with the USGS and NOAA. This project supports NSF-funded research of Kelley, Reagan, Shaw, and Stern. This project helps development of an IODP expedition. Dissertation research of one graduate student (Julia Ribeiro) will directly benefit from the cruise, and two young scientists (Wada and Guillaume Girard) will participate in a marine geoscientific expedition for the first time. This research supports the MARGINS SubFac experiment and the focus site in the Izu-Bonin-Mariana arc.
Participation of 9 US scientists (including 2 post-docs and 3 graduate students) in two JAMSTEC cruises to the Mariana arc in the Western Pacific was supported by this grant. Understanding the Mariana arc and other convergent plate margins is critical for understanding earthquakes, mineralization, and continental crust formation. The first cruise (aboard R/V Natsushima, NT1012) studied submarine arc volcanoes with ROV Hyperdolphin 3K (July 9-19, 2010). A total of 11 dives were made on 6 different Mariana volcanoes (HPD 1147-1157). These dives had a range of objectives, depending on the volcanoes: dives on Pagan, Daon, and Tracey were intended to sample primitive lavas found at the base of these volcanoes; dives in E. Diamante and W. Rota calderas were intended to sample and study mineralized regions and active hydrothermal systems; a dive to the summit of NW-Rota-1 was intended to monitor ongoing eruption. This research stimulated a proposal to NSF-OCE, which is now under review. The second cruise (aboard R/V Yokosuka; YK1012) studied the forearc SW of Guam, using manned submersible Shinkai 6500 (8 dives) and Yokosuka deep-tow camera (with minidredge, 7 dives) to study the SE Mariana Forearc Rift (SEMFR). Study of SEMFR is supported by NSF-OCE grants to Stern, Martinez, and Kelley with a cruise scheduled for Dec 2011-Jan 2012 so studies during YK1012 helped us prepare for that cruise. During this cruise we also discovered a cold seep and vent community (Shinkai Seep) in a part of the Mariaaa forearc where seeps and vent communities were previously unknown. This discovery is now being written up for submission to the journal Science.
