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dam collapsed, causing a lahar which flowed down the mountain and into the
Whangaehu River. The ERLAWS system activated at 10:47am and worked as planned. Scientists estimate that 1.29 million cubic metres (1.29 billion litres) of sulphur and water went down the Whangaehu Valley, leaving
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surrounding the area, which alert motorists and in some cases prevent entry to the danger areas. These systems incorporate automatic barrier gates, flashing lights and electronic signs warning of
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in 1995–1996. The system successfully detected and warned of an imminent lahar in March 2007. The system is being expanded to detect the wider range of lahar threats now expected on
Ruapehu.
153:, where computers monitor the data received and upload it to an external server and the ERLAWS website. When incoming measurements meet or exceed pre-set thresholds, alarms are sent via
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Following the 2007 lahar, the risks of future lahars were reassessed and judged to affect more valleys than before. The ERLAWS system will be broadened in response to the wider threat.
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97:. In 2000 the government decided to plan, design and implement ERLAWS – a complex system of sensors and preventative mechanisms to warn of an impending lahar.
85:. It was realised that as the lake refilled and rose above the level of its normal outlet, the tephra dam would eventually collapse, causing a large
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staff, and duty scientists who will then respond following predetermined plans. This alert can be up to two hours before a lahar would reach
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8.9 million cubic metres in the crater lake. This lahar was at least 50% larger than the 1953 lahar that caused the
Tangiwai disaster.
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when 151 people died as the lahar swept a railway bridge away, causing a passenger train to plunge into the
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Mt
Ruapehu Crater Lake Lahar Threat Response – Crater Lake issue – a management dilemma
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ERLAWS consists of three sites at which various sensors are located – these are:
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Fresh lahar channels are visible on
Ruapehu's eastern slopes, 27 March 2007.
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three geophones to detect the vibration of the collapse and from lahars
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254:. New Zealand Department of Conservation. Retrieved 23 April 2007.
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two geophones to detect the vibration from passing lahars.
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two geophones to detect the vibration from passing lahars
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water level sensors to detect a sudden drop in lake level
115:a buried tripwire to detect collapse of the dam
145:Signals from the sites are transmitted to the
39:Eastern Ruapehu Lahar Alarm and Warning System
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65:The 1995–1996 eruptions of Ruapehu in the
226:News report showing video of dam collapse
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248:Keys, Harry & Green, Paul (2004).
49:warning system that was installed on
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279:Emergency population warning systems
89:. Such a lahar resulted in the 1953
157:to police, district council staff,
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81:and rock, around the rim of the
131:Site 3 (near Tukino skifield)
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180:has systems installed on the
259:Next lahar may be widespread
123:Site 2 (NZ Alpine Club hut)
109:Site 1 (Crater Lake outlet)
238:YouTube video of 2007 lahar
73:left a 7-metre high dam of
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284:Volcanism of New Zealand
53:, New Zealand following
196:On 18 March 2007, the
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265:, 6 September 2007.
178:Transit New Zealand
159:Transit New Zealand
55:volcanic eruptions
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263:The Dominion Post
149:power station at
91:Tangiwai disaster
16:(Redirected from
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163:KiwiRail Network
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186:flash flooding
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147:Genesis Energy
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51:Mount Ruapehu
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79:volcanic ash
67:North Island
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61:Introduction
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83:crater lake
71:New Zealand
273:Categories
213:References
141:Monitoring
205:Expansion
167:Tangiwai
151:Tokaanu
101:Sensors
45:) is a
198:tephra
192:Events
155:pagers
75:tephra
43:ERLAWS
18:ERLAWS
87:lahar
47:lahar
37:The
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