Editing Challenger Deep (section)

===2001 – RV ''Melville''===
[[File:RV Melville (25635910745).jpg|thumb|The RV ''Melville'' was operated by the Scripps Institution of Oceanography.]]

The 2.516-ton research vessel [[BRP Gregorio Velasquez (AGR 702)|''Melville'']], at the time operated by the Scripps Institution of Oceanography, took the Cook Expedition, Leg 6 with chief scientist Patricia Fryer of the University of Hawaii from Guam on 10 February 2001 to the Challenger Deep for a survey titled "Subduction Factory Studies in the Southern Mariana", including HMR-1 sonar mapping, magnetics, gravity measurements, and dredging in the Mariana arc region.<ref>{{cite web |url=https://www.nsf.gov/awardsearch/showAward?AWD_ID=9907063 |title=Subduction Factory Studies in the Southern Mariana Convergent Margin: Side-Scan, Geophysical and Petrologic Investigations |publisher=National Science Foundation |access-date=26 November 2019 |archive-date=27 July 2020 |archive-url=https://web.archive.org/web/20200727192713/https://www.nsf.gov/awardsearch/showAward?AWD_ID=9907063 |url-status=live }}</ref><ref>Patricia Fryer, [http://siox.sdsc.edu/search.php?xml=xqdl_0_1.xml&collectionidentifier_tag=COOK06MV&collectionidentifier=COOK06MV&subject_tag=&subject=&format=&adoidentifier=&creator_tag=&creator=&timestart=&timeend=&latitudenorth=&longitudewest=&longitudeeast=&latitudesouth=&action=Run+Search&results_type=1 Report and Index of Underway Marine Geophysical Data] {{Webarchive|url=https://web.archive.org/web/20211224210758/http://siox.sdsc.edu/search.php?xml=xqdl_0_1.xml&collectionidentifier_tag=COOK06MV&collectionidentifier=COOK06MV&subject_tag=&subject=&format=&adoidentifier=&creator_tag=&creator=&timestart=&timeend=&latitudenorth=&longitudewest=&longitudeeast=&latitudesouth=&action=Run+Search&results_type=1 |date=24 December 2021 }}, Cook Expedition Leg 6, Scripps Institution of Oceanography; 2001</ref> They covered all three basins, then tracked {{convert|120|nmi|km|1|adj=mid|-long}} lines of bathymetry East-West, stepping northward from the Challenger Deep in {{convert|12|km|mi|abbr=on}} sidesteps, covering more than {{convert|90|nmi|km|1|abbr=on}} north into the backarc with overlapping swaths from their SeaBeam 2000 12&nbsp;kHz multi-beam echosounder and MR1 towed system. They also gathered [[geomagnetic|magnetic]] and [[gravity]] information, but no seismic data. Their primary survey instrument was the MR1 towed sonar,<ref>{{cite web |url=http://www.soest.hawaii.edu/HMRG/cms/ |title=Hawaii Mapping Research Group |publisher=University of Hawaii |access-date=25 November 2019 |archive-date=15 April 2021 |archive-url=https://web.archive.org/web/20210415113648/http://www.soest.hawaii.edu/HMRG/cms/ |url-status=live }}</ref> a shallow-towed 11/12&nbsp;kHz bathymetric [[sidescan sonar]] developed and operated by the Hawaii Mapping Research Group (HMRG), a research and operational group within University of Hawaii's School of Ocean and Earth Science and Technology (SOEST) and the Hawaii Institute of Geophysics and Planetology (HIGP). The MR1 is full-ocean-depth capable, providing both bathymetry and sidescan data.

Leg 7 of the Cook Expedition continued the MR-1 survey of the Mariana Trench backarc from 4 March to 12 April 2001 under chief scientist Sherman Bloomer of [[Oregon State University]].