1 / 16

TOFUA

TOFUA. Emily Malinowski and Mikaela Johnson Dept. of Geology, Colby College. 19 °45′00″S 175°04′30″W. GEOGRAPHY. Tofua is a Summit Caldera of a steep composite cone that forms the 8 kilometer wide Tofua Island, located in the country of Tonga 1,690 feet high 5 km by 6 km wide

chase-torres
Download Presentation

TOFUA

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. TOFUA Emily Malinowski and Mikaela Johnson Dept. of Geology, Colby College

  2. 19°45′00″S 175°04′30″W

  3. GEOGRAPHY • Tofua is a Summit Caldera of a steep composite cone that forms the 8 kilometer wide Tofua Island, located in the country of Tonga • 1,690 feet high • 5 km by 6 km wide • Contains a freshwater crater lake

  4. Geography Cont’d • Three major cones lie on eastern, western, and northern parts of caldera • Northern cone (Lofia) is still active • Eastern cone is dormant with three vents • Western cone is older, deeply eroded ash

  5. Plate Tectonics • Tonga was created by subduction,or where the Pacific plate is being subducted below the Australian plate • This point of converging plates is called the Tonga Trench, which is approximately 10,882 meters deep at its deepest point

  6. ORIGINS • In 1643, Tofua Island was first spotted by a European explorer, Abel Tasman • Tofua was formed after a Stratovolcano erupted in 1774, leaving the summit caldera in its place • Captain James Cook (1728-1779) witnessed this first recorded eruption of that Stratovolcano • The first to set foot on the island however was Captain William Bligh in 1789

  7. Activity • Most reported eruptions have been small, produced by the Lofia Cone • An eruption in the mid 1900s caused most of the inhabitants to evacuate • March 2009--Xavier Rosset, a Swiss adventurer, reported minor activity at Tofua • July 2011--The Tonga Meteorological Services and pilot observations noticed a cloud from Tofua rising to 1.3 km in height. • August 14th, 2012 a 3,000 foot high ash cloud was observed by a pilot flying over the Tonga Islands. There was a debate on whether the clouds were an actual eruption or smoke from fires.

  8. Tofua Formations • Hamatua Formation • Hokula Froth Lava • Kolo Formation • Lofia Formation

  9. Hamatua Formation -Pre caldera -First eruptions -Approx. 1600 feet thick Pyroxene Dacite Basaltic Andesite Pyroxene Andesite

  10. Hokula Froth Lava -Directly overlies the Hamatua Formation -Contains “Frothy Lava”

  11. Kolo Formation Lapilli Tuff-Breccia Tuff Volcanic Ash

  12. The Lofia Cone • Largest, northernmost cone • 400 feet deep • Lava floor • Fumarolic state • Pyroclastic deposits around the area

  13. Monitoring • The Hawaii Institute of Geophysics • The Wellington Volcanic Ash Advisory Centre Rock coring tool used in paleomagnetic study

  14. Life on the Island • Tofua Island has been uninhabited for thirty years, however farmers travel to grow Kava • The soil is extremely rich and fertile, with various plants an animals • There are forests, tropical bush, and desert tundra • Occasional cyclones hit the area during the hurricane season

  15. Tourism • Until 1999 a plane ran flights to Tofua, however the lack of interest shut down operations. Today tourists can visit the island by boat. • Tofua is most popular and safe for hiking and swimming. • Visitors can hike the Lofia Cone and look down into the lava

  16. Bibliography • http://www.volcanodiscovery.com/tofua-eruptions.html • http://en.wikipedia.org/wiki/Tofua • http://www.volcano.si.edu/world/volcano.cfm?vnum=0403-06= • http://tonga.southpacific.org/haapai/tofua.html • http://proven-travel.com/tofua/ • http://teachtonga.com/geography.htm • http://theextinctionprotocol.wordpress.com/2012/08/14/62-tofua-volcano-erupts-sending-ash-cloud-3000-feet-above-tonga-islands/ • https://docs.google.com/a/colby.edu/viewer?a=v&pid=gmail&attid=0.1&thid=13c735945b0c5568&mt=application/pdf&url=https://mail.google.com/mail/u/0/?ui%3D2%26ik%3D4b2b57da4b%26view%3Datt%26th%3D13c735945b0c5568%26attid%3D0.1%26disp%3Dsafe%26realattid%3Df_hcdrqwz20%26zw&sig=AHIEtbQrpaWbvTJe1j2K1YVhV-aSxu19IA • PICTURES: • http://www.volcano.si.edu/world/volcano.cfm?vnum=0403-06=&volpage=photos&photo=107097 • http://www.travelgrove.com/blog/wp-content/uploads/tofua.jpg • http://www.google.com/imgres?q=tonga+islands&hl=en&client=safari&sa=X&tbo=d&rls=en&biw=1280&bih=663&tbm=isch&tbnid=qJEr2W_-XiWzkM:&imgrefurl=http://geography.howstuffworks.com/oceania-and-australia/geography-of-tonga.htm&docid=6I3mFBcNKp4yCM&imgurl=http://static.ddmcdn.com/gif/willow/geography-of-tonga0.gif&w=273&h=228&ei=_4_9UJHfHozO0QH7m4HoBg&zoom=1&iact=rc&dur=454&sig=109138024570501102308&page=1&tbnh=143&tbnw=171&start=0&ndsp=20&ved=1t:429,r:2,s:0,i:104&tx=136&ty=91 • http://www.google.com/imgres?q=tofua&hl=en&client=safari&tbo=d&rls=en&biw=1280&bih=663&tbm=isch&tbnid=ippFzUJAzAZAEM:&imgrefurl=http://www.nautilussubmarine.com/forum/viewtopic.php%3Ff%3D36%26t%3D382%26start%3D20&docid=Efn9jwbVYxmIuM&imgurl=http://www.photosntravels.com/dancyn/albums/album34/tofua_005.jpg&w=1024&h=768&ei=IZD9UOCSKO7C0AHhsYDgDQ&zoom=1&iact=rc&dur=345&sig=109138024570501102308&page=1&tbnh=139&tbnw=200&start=0&ndsp=25&ved=1t:429,r:0,s:0,i:81&tx=82&ty=33 • http://www.google.com/imgres?q=captain+cook&hl=en&client=safari&tbo=d&rls=en&biw=1280&bih=663&tbm=isch&tbnid=j110B8N5wVz4fM:&imgrefurl=http://en.wikipedia.org/wiki/James_Cook&docid=DyaNqdXffoAo0M&imgurl=http://upload.wikimedia.org/wikipedia/commons/thumb/7/76/Captainjamescookportrait.jpg/220px-Captainjamescookportrait.jpg&w=220&h=275&ei=m5D9UJvBGfLh0wHE8ICQDQ&zoom=1&iact=hc&vpx=4&vpy=147&dur=46&hovh=220&hovw=176&tx=81&ty=140&sig=109138024570501102308&page=1&tbnh=134&tbnw=108&start=0&ndsp=29&ved=1t:429,r:0,s:0,i:147 • http://www.lonelyplanet.com/maps/pacific/tonga/ • http://geology.about.com/od/more_igrocks/ig/extrusives/Tuff-from-Green-Valley.htm • http://www.volcano.si.edu/volcanoes/region04/tonga/tofua/3402tof4.jpg • http://www.volcano.si.edu/volcanoes/region04/tonga/tofua/3607tof1.jpg • http://tbarnes.co.uk/TimsPages/TRAVEL/Tonga/plane.htm

More Related