Ruby Seamount
{{Short description|Seamount chain east of Australia that includes Lord Howe Island}}
{{Use dmy dates|date=June 2024}}
{{Infobox seamount
| name = Ruby Seamount
| depth = {{convert|175|m|abbr=on}}
| height =
| summit_area =
| location = Pacific Ocean
| group = Izu–Bonin–Mariana Arc
| coordinates = {{coord|15|37|12|N|145|34|12|E|format=dms|display=inline,title}}
| country = Commonwealth of Northern Mariana Islands, United States
| type = Seamount
| age = {{Geological range|2|0|ref=}}
| discovered =
| pushpin_map =
| relief =
| last_eruption = 15 September 2023
| map = File:Ruby bathymetry map 600.jpg
| map_size =
| map_caption = Ruby Seamount bathymetry
| image = File:Map Mariana Islands volcanoes.gif
| image_caption = Major volcanoes of the Mariana Islands
| label =
}}
Ruby Seamount is an active volcanic seamount in the Northern Mariana Islands region of the Pacific Ocean about {{convert|50|km|abbr=on}} north-west of Saipan.{{cite web|url=https://volcano.si.edu/volcano.cfm?vn=284202|title=Global Volcanism Program: Ruby|access-date=20 September 2023}}{{cite web|url=https://volcanoes.usgs.gov/hans2/view/notice/DOI-USGS-NMI-2023-09-19T16:42:00-08:00|title=Northern Mariana Islands Volcano Observatory Daily update U.S. Geological Survey Wednesday, September 20, 2023, 11:10 AM ChST (Wednesday, September 20, 2023, 01:10 UTC)
|access-date=20 September 2023}} It is in a region where the Pacific Plate is subducting under the Philippine Sea Plate producing arc volcanism.
Eruptions
Geology
Ruby Seamount is a stratovolcano with a more shallow southern peak, and is part of the nine volcano Southern Seamount Province of the Mariana Arc, in the Izu–Bonin–Mariana Arc.{{cite journal| first1=Robert J| last1=Stern| first2=Sherman H| last2=Bloomer| first3=Ping-Nan| last3=Lin| first4=N Christian| last4=Smoot| title= Submarine arc volcanism in the southern Mariana Arc as an ophiolite analogue| journal=Tectonophysics| volume=168| issue=1–3| year=1989|pages=151–170| issn=0040-1951| doi=10.1016/0040-1951(89)90374-0| bibcode=1989Tectp.168..151S}}{{rp|151}} Its location is consistent with it being a back-arc extension associated volcano. Samples of lava have been characterised as arc tholeiitic basalts, suggestive that the magma source was from mantle overlying, not beneath, the subducting Pacific Plate.{{cite journal| last1=Marlow |first1=MS| last2=Johnson| first2=LE| last3=Pearce| first3=JA| last4=Fryer| first4=PB| last5=Pickthorn| first5=LB| last6=Murton| first6=BJ| title=Upper Cenozoic volcanic rocks in the Mariana forearc recovered from drilling at Ocean Drilling Program Site 781: Implications for forearc magmatism| journal=Journal of Geophysical Research: Solid Earth| date=10 October 1992| volume=97| issue=B11| pages=15085–97|doi= 10.1029/92JB01079|bibcode=1992JGR....9715085M |url=https://orca.cardiff.ac.uk/id/eprint/8478/1/Marlow%201992.pdf }}{{rp|pp=15092–3}} The age of the volcano is unknown but nearby basalts have been dated at about 2 million years old,{{rp|pp=15094–6}} so it likely started forming more recently than this.
Hydrothermal activity was demonstrated in 2006 with alkaline, ferrous ion and carbon dioxide venting at {{convert|200|m|abbr=on}} depth.{{cite journal| last1=Resing| first1=JA| last2=Baker| first2=ET| last3=Lupton| first3=JE| last4=Walker| first4=SL| last5=Butterfield| first5=DA| last6=Massoth| first6=GJ| last7=Nakamura| first7=KI| title=Chemistry of hydrothermal plumes above submarine volcanoes of the Mariana Arc|journal=Geochemistry, Geophysics, Geosystems| year=2009| volume=10| issue=2|doi=10.1029/2008GC002141| doi-access=free| bibcode=2009GGG....10.2009R}}{{rp|pp=7,11}} The ratio of CO2 / 3He flux observed at Ruby is amongst the highest ever reported, which is consistent with volcanism involving a deep magma source from slab derived carbonate containing rocks.{{rp|pp=18}}
= Depth revision =
Prior to the 1995 eruption the depth was accepted as {{convert|230|m|abbr=on}}, but several reports of shallower depths followed the eruption including one of only about {{convert|60|m|abbr=on}} exist. A high quality survey in 2003 gave a depth of {{convert|180|m|abbr=on}} with the peak of North Ruby having a depth of {{convert|726|m|abbr=on}}.{{cite web|url=https://oceanexplorer.noaa.gov/explorations/03fire/logs/summary/marianas_cruisereport.pdf|title=Submarine Ring of Fire 2003 – Mariana Arc R/V T. G. Thompson Cruise TN-153 February 9 - March 5, 2003 Guam to Guam| last1= Merle| first1=Susan| last2=Embley| first2=Robert W.| last3=Baker| first3=Edward T.| last4=Chadwick| first4=Bill|access-date=20 September 2023}}{{rp|16}} The next high quality survey in 2006 gave a new depth of {{convert|175|m|abbr=on}}.{{rp|11}}
Ecology
A unique ecosystem of crabs and limpets has been described on the flanks of the volcano.{{cite web|url=https://oceanexplorer.noaa.gov/explorations/06fire/logs/may3/may3.html| title=NOAA:Explorations:Submarine Ring of Fire 2006:Logs:Ruby Submarine Volcano|access-date=20 September 2023}}
Name
It was first named as Ruby Volcano in the 1973 paper that described some of the 1966 eruption evidence.{{cite journal| last1=Johnson| first1=Rockne H| title=Acoustic observations of nonexplosive submarine volcanism| journal= Journal of Geophysical Research| volume=78 |issue=26| year=1973| pages=6093–6096|doi=10.1029/JB078i026p06093| bibcode=1973JGR....78.6093J}}
References
{{reflist}}
External links
- [https://www.youtube.com/watch?v=vFb43GhJIbI Youtube:The United States Has a New Volcanic Eruption; Ruby Seamount]
{{Northern Mariana Islands||collapse_state=collapsed}}
Category:Izu–Bonin–Mariana Arc