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Mount Ruapehu, or just Ruapehu, is an active stratovolcano, situated at the southern end of the Taupo Volcanic Zone. It is the highest point on the North Island of New Zealand. Ruapehu contains three major peaks: Tahurangi (2,797m), Te Heuheu (2,755m) and Paretetaitonga (2,751m). Ruapehu is frequently active, and is one of the largest active volcanoes in New Zealand. It is part of Tongariro National Park.

1 Volcanic Activity

The volcano has erupted in 1861, 1895, 19031903 has the latest occurring solstices and equinoxes for 400 years, because the Gregorian calendar hasn't had a leap year for seven years or a century leap year since 1600. Events January 1 Edward VII of the United Kingdom is proclaimed Emperor of India, 1945Events January January 5 The Soviet Union recognizes the new pro-Soviet government of Poland. January 7 British General Bernard Montgomery holds a press conference in which he claims credit for victory in the Battle of the Bulge. January 12 World War II:, 1969For other uses, see Number 1969. For the movie, see 1969 (movie). Events January January 1 Australian media baron Rupert Murdoch purchases the largest selling British Sunday newspaper The News Of The World January 5 The Derry Riots leave over 100 people i, 19711971 is a common year starting on Friday (click for link to calendar). Events January January 1 British divorce Reform Act comes into force January 2 66 die in stairway crush at Rangers v Celtic football match, Glasgow, Scotland. See Ibrox disaster. Janua, 1975Events January January 1 Watergate scandal: John N. Mitchell, H. Haldeman, John D. Ehrlichman are found guilty of the Watergate cover-up and are sentenced to 30 months to 8 years in jail on February 21 January 5 The Tasman Bridge in Tasmania, Australia, i, 19881988 is a leap year starting on Friday (click on link for calendar). Events January January 2 Georgia celebrates its bicentennial statehood. January 9 Connecticut celebrates its bicentennial statehood. January 26 Australia celebrates its bicentennial day., 1995 and 1996.

Between eruptions, a crater lake forms from melting snow. Where an eruption has deposited a tephra dam across the lake's outlet, the dam may collapse after the lake has risen above the level of its normal outlet, causing a mud flow known as a lahar.

A lahar on December 24 1953 caused the Tangiwai disaster, with the loss of 151 lives, when the Tangiwai railway bridge, across the Whangaehu river, collapsed just before an express train crossed the bridge while the lahar was in full flood. It was already known that the river had partially undermined one of the bridge piers and it is believed that the lahar finished the job, causing the bridge to collapse. Although warned of the collapsed bridge, the train driver was unable to stop the train in time.

Spectacular eruptions occurred during 1995 and 1996. Ruapehu had been showing signs of increased activity since late November 1994, with elevated Crater Lake temperatures and a series of eruptions that increased in intensity over about 9 months. Several lahar were observed, both in the Whangaehu river and other areas of the mountain between September 18 and September 25 1995, indicating the Crater lake was being emptied by the eruptions. The Department of Conservation immediately issued hazard warnings and advised all people to keep off the mountain. This eruption also ended the ski season on the mountain. The eruption cloud also disrupted air travel, occasionally closing airports and the central north island airspace. Episodic eruptions continued until the end of November 1995.

Within hours of a major eruption during the night being reported on September 25 1995, news media were trying to get live video of the eruption and amateur photographers had published eruption images on the World Wide Web. A webcamera, dubbed the world's first " VolcanoCam ", was also set up. Since then Ruapehu has been monitored by at least one and sometimes several volcanocams.

Another, smaller, eruption phase began on the morning of June 17 1996, again the mountain was closed to visitors and the skifields were closed for the season, this time before they even opened.

After the 1996 eruption, it was recognised that a catastrophic lahar could again occur when the crater lake burst the volcanic ash dam blocking the lake outlet. This is the same mechanism that caused the 1953 lahar. It is estimated that such a lahar might occur from late 2004 onwards and the local authorities are currently planning for managing this event safely when it occurs.