Geology Home Page physical geology historical geology planetary gems
Roger Weller, geology instructor
by Daniel Bonser
Physical Geology Fall 2015
Mt. Fuji, Mt. Fujiyama, or Fuji san (富士山) is a nearly perfect stratovolcano and the highest peak in Japan standing at about 3776 meters tall (12,388 feet). Mt. Fuji is located on the border between the prefectures of Yamanashi and Shizuoka (“Mt. Fuji”). One of the best places to view Mt Fuji is at the northern base of Mt Fuji in The Fuji Five Lake (富士五湖, Fujigoko) region. The lakes are name Kawaguchiko, Saiko, Yamanakako, Shojiko, and Motosuko (“Fuji Five Lakes”).
Mt. Fuji is one the three holy mountains in Japan, and the other sacred mountains are Mount Tate and Mount Haku. Though they are called mountains they are really volcanoes. (“The three holy mountains”) Konohana Sakuya Hime (木花之開耶姫, Princess Blossoms of the Trees) is said to be the kami of Mount Fujiyama (“Konohana Sakuya Hime”) and, is the symbol of our delicate earthly life. According to the Shinto religion she is the daughter of the mountain god Ohoyamatsumi, and is often considered the avatar of Japanese life. That is not surprising considering that the sakura (cherry blossom) is her symbol. Kono-hana (Konohana Sakuya Hime) is also goddess of all volcanos and especially Mt Fuji. She is the wife of Ninigi. Konohana Sakuya Hime is believed to keep Mt Fuji from eruption. Though it seems unsuccessful, because her shrines at Kirishima have been destroyed many times by volcanic eruptions. (“Princess_Konohanasakuya/Origin”)As the Sakura peddle falls on the foot of the mountain the Princess of Blossoms cries, for the season is gone. May the next bring more happiness to the seasons that comes after, because the blossoms of this generation have fallen and are no more.
Due to the volcanic nature of the region Mount Fuji is well known for its hot spring. Many onsen (Which are natural hot springs (温泉) have dotted the country side for hundreds of years, and are considered a great way to relax. Seeing that Japan consists of a chain of volcanic islands onsens exist all over japan and are very popular. In fact every region in Japan inundated with its own fair share of hot springs and resort towns, which happen to come with them. (“Onsens”).
There have been many eruptions in Mt. Fuji’s past, and most notably the most resent eruption was in 1707. Mt. Fuji is still an active volcano, and the last eruption was announced with a massive 8.4 magnitude earth quake, on Oct, 26, 1707. The earth quake devastated the main island of Honshu, and was followed by several smaller earth quakes. On Dec, 16, 1707, the eruption stated from a new vent on the southeast side of Mt Fuji a sub-Plinian column of ash and pumice, after only 6 hours of the eruption it evolved into basaltic lava fountaining. Sadly the eruption devastated the town of Subassiri 10 km away destroying 72 homes and 3 Buddhist temples just on the first day. All over the south Kanto plain, Tokyo, and northwest area of the Pacific Ocean about 280 km from the volcano. It is estimated that a volume of 0.68 cubic miles of magma was erupted over a 16 day period. A series of violent eruptions through December, 27, 1707, the eruption calmed then ended on January, 1, 1708(“Mt. Fuji Volcano.”).
Mt. Fuji formed around 100,00 years ago from the base of Mt. Komitake.
Forming over two generations of volcanic activity the shape of Mt Fuji’s
beautiful cone and over time transforming from the old Mt. Fuji into the Mt.
Fuji we all know and love today. According to recent research suggests
there could have been a volcanic predecessor to Mt. Komitake. The Hoei
crater was formed by Mt Fujiyama’s 1707, eruption which was during the Edo
period and a vast volcanic plane to the eastern side of the mountain was formed
by volcanic ash. (“Mt Fuji Nature”)
If an eruption was to happen today it would be a real deserter, for both the locals and the people in the surrounding prefectures. A new plan is in preparation for a possible eruption has been outlined to evacuate 1.2 million people in case Mt Fuji erupts. Around 750,000 people would have to be evacuated from the prefectures of Shizuoka and Yamanashi, and another 470,000 that currently reside in Kanagawa. The health problem caused by the ash in surrounding prefectures would be devastating. A large portion of the locals in the three prefectures reside in wooden houses, and sadly if the volcano ever erupts the homes are at risk of being crushed under heavy volcanic ash. There are an estimated 406,000 people in Kanagawa, 62,000 in Shizuoka, and 1,000 in Yamanashi that would be affected by 30 cm or more of heavy. A hazard map made in 2004, shows which areas that are in high risk of being affected by volcanic ash(“1-2- million people to evacuate if Mt Fuji Erupts”).
The same geology that caused the Kobe earthquake is the same geology that feeds Mt Fuji. Japan sits on a subduction zone where the Pacific Plate slips under the Eurasian Plate and the Philippine Plate, and the Philippine Plate is slipping under the Eurasian Plate. The Kobe earthquake was the result of a sudden movement between the Philippine Plate and the Eurasian Plate. (“The Kobe Earth Quake”)
“Fuji Five Lakes (Fugigoko).” Japan
Guide.com. Japan-guide.com. 16 Apr. 2014. Thru. 12 Nov. 2015.
“Mt. Fuji.” Japan Guide.com. Japan-guide.com.
31 Dec. 2014. Thru. 12 Nov. 2015.
“Mt. Fuji Volcano.” VolcanoDiscovery.com. VolcanoDiscovery, n.d. Web. 12 Nov. 2015.
“1-2- million people to evacuate if Mt Fuji Erupts” Japandailypress.com. Author Maan Pamintuan-Lamorena. Feb, 07, 2014. Thru, 12, 2014 http://japandailypress.com/1-2-million-people-to-evacuate-if-mt-fuji-erupts-says-local-governments-new-plan-0743812/by Edwin Bernbaum, University of California Press, 1997), “Onsens www.japan-guide.com” http://www.japan-guide.com/e/e2292.html, “Princess_Konohanasakuya/Origin http://ayakashi-ghost-guild.wikia.com/wiki/Princess_Konohanasakuya/Origin” http://ayakashi-ghost-guild.wikia.com/wiki/Princess_Konohanasakuya/Origin, “The Kobe Earth Quake http://kobe1995.wikispaces.com/3.+The+Kobe+Earthquake” http://kobe1995.wikispaces.com/3.+The+Kobe+Earthquakehttp://www.pref.shizuoka.jp/kankyou/ka-070/fujisanpage/otherlanguage/en/nature2.html “The three holy mountains http://earlywomenmasters.net ”,