Joseph Gilbert Seamount

{{short description|Continental fragment seamount west of New Zealand}}

{{Use dmy dates|date=April 2022}}

{{Infobox Seamount

| name = Joseph Gilbert Seamount

| depth = {{Convert|2400|m|ft|abbr=on}}

| height =

| map = Zealandia, topographic map.jpg

| map_caption = Topographic map of Zealandia, showing Gilbert Seamount

| summit_area =

| location = Tasman Sea

| group =

| coordinates = {{coord|42|52|18.1|S|164|4|0.1|E|display=inline, title}}

| country = New Zealand

| type = Seamount (continental fragment)

| volcanic_group =

| age =

| last_eruption =

| discovered =

| discovered_by =

| first_visit =

| translation =

| language =

| pronunciation =

| photo =

| photo_alt =

| photo_caption =

}}

Joseph Gilbert Seamount is a large seamount in the Tasman Sea located {{Convert|450|km|mi|abbr=on}} west of the South Island of New Zealand at the southern edge of the Lord Howe Rise.{{cite web|url=http://www.marineregions.org/gazetteer.php?p=details&id=33643|title=Marine Gazetteer Placedetails|accessdate=2020-03-15}}{{cite web|last=Wood|first=R.|url=https://www.gns.cri.nz/static/unclos/pdfs/44wood.pdf|title=Finding the continental shelf – integration of geology and geophysics|publisher=GNS Science|year=2002|pages=3, 4|accessdate=2020-03-15}} It has an elongated northwest–southeast trend, covering an area of about {{Convert|11500|km2|mi2|abbr=on}} and rising to {{Convert|2400|m|ft|abbr=on}} below sea level.

The seamount is a continental fragment that rifted away from the South Tasman Rise and Challenger Plateau during the Cretaceous breakup of Gondwana.{{Cite web|last1=Gaina|first1=C.|last2=Müller|first2=R. D.|last3=Brown|first3=B.|last4=Ishihara|first4=T.|url=http://www.geosci.usyd.edu.au/users/dietmar/Pdf/Gaina_etal_GSA_SpecPap2003.pdf|archiveurl=https://web.archive.org/web/20080723174911/http://www.geosci.usyd.edu.au/users/dietmar/Pdf/Gaina_etal_GSA_SpecPap2003.pdf|archivedate=23 July 2008|title= Microcontinent formation around Australia|publisher=Geological Society of Australia|volume=22|year=2001|page=399}} It is separated from the easterly Challenger Plateau by a {{Convert|4400|m|ft|abbr=on}} deep saddle.

Joseph Gilbert Seamount is named after Joseph Gilbert, captain of {{HMS|Resolution|1771}} on the second voyage of James Cook, and has been known under a variety of names throughout its history, including Gilbert Ridge, Gilbert Seamount Complex and Gilbert Seamount.