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Volcanic Landslides

Volcano camera reveals some of its other secrets.

Images from our camera on the north rim at White Island are usually dominated by the vivid white gas and steam plumes from the active vents. What is less obvious is the source of the single largest natural event on the volcano in historic time - the 1914 landslide. This was more deadly than any eruption has been historically.

 

Around 9 or 10 September 1914, a large portion of the Main Crater wall at White Island collapsed onto the crater floor and consumed a mining camp. Sulphur was mined for the manufacture of sulphuric acid and fertiliser.  At the time this was headlined as “the greatest eruption in the Dominion since Tarawera on June 10, 1886” (Bay of Plenty Times 21 September 1914). Ten sulphur miners perished; the only survivor was the company cat, Peter the Great.  

The exact date and timing of the landslide is not well known. The island was visited by a launch from Opotiki on 15 September, however the launch master was not able to attract the attention of people ashore and could not land due to the sea conditions and darkness. He returned on 19 September. On landing he was immediately aware that a disaster had struck. He returned to the mainland and organised a rescue mission, but no trace of the miners was ever found.  An unusual cloud of ‘black smoke’ was noted from the mainland above the island on 10 September and this is thought to be ‘dust’ from the landslide and the most likely day of the event.

The source area of the landslide can often be seen in images from our web camera on the north rim and extends from the crater floor to the sky line. At the time of the 1914 landslide much of the Main Crater floor was covered by a crater lake, much larger than the lake there today.  The landslide came down into this lake, mixed with water and then flowed across the Main Crater floor and into the sea. The landslide has left hummocky mounds across the crater floor. The top of these mounds are great places to take panorama pictures of the island. Scientifically this is classed as a debris flow and the mounds are known as debris mounds. Similar deposits are found around many New Zealand volcanoes (especially  Ruapehu and Taranaki).   

Landslides are a common feature of White Island due to the high steep walls and weak nature of the material in the walls. The latest moderate size landslide occurred during heavy rainfall in July 2004, when a landslide off the north wall crossed half way across the crater floor. The landslide dammed some of the small streams on the crater floor. But this was very small compared to the 1914 one, only covering about 7% of the area of the 1914 one.

Gas flights have been completed at all of our active volcanoes this week.

The GeoNet volcano gas team like to make gas flights about once a month at our active volcanoes; White Island (Whakaari), Ruapehu and Tongariro (Te Maari). However the weather has a big say in this. This week we have had a great run of fine weather and the team has made measurements at all of our active volcanoes.

We mount our gas instruments in a modified Scenica aircraft operated by HeliPro. Some of the instruments ‘sniff’ the gas, while others look up through the plume.  At White Island we also have two permanent gas sensors (MiniDOAS) that give us addition data between the flights. You can find out more about the methods we use here or watch the video clip to see the team in action. We measure the amount of CO2 (carbon dioxide), SO2 (sulphur dioxide) and H2S (hydrogen sulphide).

On Monday Tongariro was flown, this is the most difficult one for us due to the topography around the vents, so we can not fly too close or low.  When the wind is from the right direction we can also mount our gas gear in a car and measure it by driving along the road under the volcano. Since the eruptions in 2012 the vents at Te Maari have been pumping out a lot of volcanic gas. The amount of gas has remained steady for the last year and a half; CO2 ranging 180 to 630 tons per day, while SO2 ranges 18 to 60 tons per day and H2S ranges 3 to 40 tons per day.

On Tuesday Mt Ruapehu was flown. The amount of gas from here is usually low and sometimes we can not detect the gases at all. It’s quiet different if the volcano is active and erupting, then it produces a lot of gas. The crater lake also has an affect, absorbing some of the gas. The amount of gas output since 2010 has typically ranged 50 to 2000 tons per day for CO2, while SO2 ranges 0 to 190 tons per day and H2S ranges 0 to 0.4 tons per day.

Then on Wednesday, a flight was completed at White Island. This is by far the easiest one to do as it always has some gas coming out of it and there are no other hills around.  White Island was active in 2012, when some small eruptions occurred. Since then the amount of gas has declined slightly. Recently the CO2 has ranged 1050 to 2600 tons per day, while SO2 ranged 360 to 2000 tons per day and H2S ranges 4 to 80 tons per day.

 

Thursday 28 August 2014 11:00 am, Earthquake activity near Whakaari / White Island. Volcanic Alert Level remains at 1

 

The GeoNet seismic network has detected a sequence of small earthquakes near White Island this morning. The largest event is magnitude 3.3 and was located within  5km of the island.  The earthquake sequence is continuing.

Since 9.25 am today we have located 5 earthquakes near White Island and recorded several smaller ones that cannot be located. All of the earthquakes appear to be within 5 km of White Island The size of the locatable events ranges from magnitude 2.5 to 3.3 and all are shallow (less than 10 km depth).

We have not recorded or observed any changes on the volcano since the earthquakes started. Yesterday we measured volcanic gases at the island and the results do not show any changes in the amount of gas been released from the volcano.

Earthquake sequences are relatively frequent near White Island and have not resulted in changes in activity on the island in the past.

White Island remains in a state of volcanic unrest. A range of eruptive activity can occur under these conditions and eruptions can start with little or no prior warning. Larger eruptions can eject mud and rocks and may impact the crater floor area. The Volcanic Alert Level remains at Level 1.

GNS Science is continuing to closely monitor the activity at White Island (and other New Zealand volcanoes) through the GeoNet project.

Want to learn more about volcano monitoring, see here ?

Want to learn more about the Volcanic Alert Levels, see here.

 

Contact:

Duty Volcanologist: Tony Hurst

Volcano information: Brad Scott

07 374 8211

New Zealand uses a Volcanic Alert Level system that defines the current level of activity at our active volcanoes. A new Volcanic Alert Level system that better meets the needs of its users is now active. The new system can be accessed on the GeoNet website

The former Volcanic Alert Level system was reviewed between 2010 and 2014 as part of a research project that looked at improving the communication of information about volcanic activity. This research found that the system was perceived to be too complex, and that developments in volcano monitoring over the past 20 years have created an opportunity to improve the system. The improvements in volcano monitoring have come about through the GeoNet project (funded by EQC). Ways to make the system more understandable and useful were identified during the revision process, leading to the development of a ‘new’ Volcanic Alert Level system, which is now in use.

A Volcanic Alert Level system was first developed before the Ruapehu eruptions in 1995, and has been in use since then. The Volcanic Alert Level system has been used for eruptions at Ruapehu, White Island, Raoul Island and Tongariro (Te Maari). Changes in the new system include having just one system for all volcanoes in New Zealand (previously there were two), restructuring the system so that there is an additional level for ‘moderate to heightened volcanic unrest’ (instead of just one level for all volcanic unrest), and adding in information about the most likely hazards that will be seen for each level of volcanic activity. The number of levels in the new system remains unchanged, and ranges from 0 (no volcanic unrest) to 5 (major volcanic eruption). No changes have been made to the International Aviation Colour Code system.

To find out more information on the new Volcanic Alert Level system, visit the GeoNet website. To learn about volcanic hazards visit the GNS web site, and to find out what to do before, during and after volcanic activity, visit the MCDEM web site.

Information Contact:
Brad Scott

Volcano update   

All of New Zealand’s monitored volcanoes have been assigned a level, using the new Volcanic Alert Level system. Fortunately they have been quiet for the last few months. Listed below are some of the highlights of recent activity at the volcanoes and their new Volcanic Alert Level.

White Island: Volcanic Alert Level 1
  • There were short lived eruptions at White Island on 8 and 11 October 2013 that affected the Main Crater floor. The major change since then has been the reestablishment of a hot crater lake (55-60 C), which is slowly growing larger.
Ruapehu: Volcanic Alert Level 1
  • The most recent eruption at Ruapehu was on 25 September 2007. The active crater is occupied by a warm crater lake, which is currently in a heating phase. As at 1 July 2014 the lake temperature was about 36 °C. The temperature of the Crater Lake at Ruapehu typically ranges from about 15 to 45 °C over 12-14 months.
Te Maari (Tongariro): Volcanic Alert Level 1
  • Eruptive activity occurred from Te Maari on 6 August and 21 November 2012. Since that time the active vent has remained very hot (over 400 °C on 2 May 2014) and continues to emit volcanic gases, especially CO2 and SO2. Steam and gas plumes are often present from the Te Maari vents.

All of our other active volcanoes are on Volcanic Alert Level 0.

Frequently Asked Questions 

Q: Why change the old system?
A: One of the challenges of a Volcanic Alert Level System is to provide a system that can be used for a range of different volcanoes. The old system was used successfully through many eruptions, but user groups told us that the old system was too complex. The volcano monitoring scientists found that changes in volcanic unrest couldn’t be properly communicated using only one level.

Q: What happens if a volcano erupts around 1 July, when the Volcanic Alert Level system is due to change over to the new version?
A: The change will still go ahead on 1 July. This means that the Volcanic Alert Level for the erupting volcano will change on 1 July to match the new system. Information will be available on the GeoNet website.

Q: How did you come up with the new system?
A:  The old system was investigated as part of a PhD research project at Massey University. The research involved volcanologists at GNS Science, other scientists in New Zealand, and agencies that use the Volcanic Alert Level system. The purpose was to find out what worked well and what didn’t. The new system was developed from findings of the research project, in consultation with the Ministry of Civil Defence and Emergency Management, GNS Science and many other user groups.

Q: Will the new Volcanic Alert Level system result in any noticeable differences in the way erupting volcanoes are managed?
A: The new Volcanic Alert Level system is building on the old one, which we have lots of experience with. The new one is removing some of the former complexity and giving stronger guidance in dealing with volcanic unrest. We expect a smooth transition to the new system, which is designed to more accurately reflect the changing moods of New Zealand's volcanoes. This will lead to more efficient management of volcano emergencies and more clarity in messages about volcanic activity.

Q: How do I find out if the Volcanic Alert Level changes?
A: When the Volcanic Alert Level is changed, GeoNet sends out information in a Volcanic Alert Bulletin. Volcano Alert Bulletins are distributed to responding agencies, the public and media, and on social media (Facebook and Twitter). The current levels are shown on the GeoNet webpages.

Q: What is the difference between "minor volcanic unrest" and "moderate to heightened volcanic unrest"?
A: ‘Minor volcanic unrest’ means there are signs of life at the volcano, but the likelihood of an eruption is small. ‘Moderate to heightened volcanic unrest’ means that the signs of life at the volcano are stronger, and that there is a higher likelihood of an eruption developing. Being able to distinguish between these two levels of unrest due to advances in GeoNet volcano monitoring is an important part of the need for a change in the Volcanic Alert Level system.

Q: What is the difference between a minor, moderate and major volcanic eruption?
A: The differences relate to the magnitude of the eruption, and the area being impacted by the eruptions. A minor eruption will most likely create hazards near the eruption vent, such as the eruptions at White Island in 2013. A moderate eruption will most likely produce eruption hazards that will affect areas on the volcano – for example, the 1995-96 eruptions of Ruapehu.  A major eruption will most likely cause widespread hazards beyond the volcano. An example of a major eruption in New Zealand was the 1886 eruption at Tarawera. It is important to know that some eruptions will often have effects far from the volcano, even when caused by a minor eruption – these are ashfall, lahars and lava flows.

Q: What does it mean by "eruption hazards near vent"?
A: Minor volcanic eruptions are mainly hazardous in areas within a few hundred meters of the active vent. Typical hazards are from small explosions and will be ballistics (flying rocks); jets of rock, mud and steam; volcanic ash; and sometimes pyroclastic density currents (fast-moving hot ash and steam clouds). Hazard maps show the likely extent of volcanic hazards.

Q: What does it mean by "eruption hazards on and near volcano"?
A: Moderate volcanic eruptions are hazardous to areas near the vent, on the flanks of the volcano, and around the base of the volcano (i.e., within about 10 km of the vent). Typical hazards include explosions that produce ballistics (flying rocks), volcanic ash, pyroclastic density currents (fast-moving hot ash and steam clouds), lava flows and lahars. Some of these hazards may extend beyond the volcano. Hazard maps show the likely extent of volcanic hazards.

Q: What does it mean by "eruption hazards on and beyond volcano"?
A: Major volcanic eruptions are very large and will cause significant impacts near the vent and on the volcano, as well as areas further afield (i.e., more than 10 km from the vent). The most widespread and common hazard is volcanic ash, which can be carried tens to hundreds of kilometres downwind from the volcano. Other hazards like collapsing lava domes, landslides, pyroclastic density currents (fast-moving hot ash and steam clouds), lava flows and lahars may also extend a long way from the volcano. Hazard maps show the likely extent of volcanic hazards.

Q: What should I do before, during and after a volcanic eruption?
A: To find out what to do before, during and after a volcanic eruption, visit the Get Ready Get Thru website. You can also find information on the GNS Science website. 

Q: How can I find out more about New Zealand’s volcanoes, and volcanic hazards?
A: Click here to learn more about New Zealand’s volcanoes, and here for information on volcanic hazards (there is also a glossary of volcano terms). The GeoNet website shows the current level of activity at the volcanoes, and contains information on monitoring at our volcanoes, and about recent eruptions. There are also lesson plans for schools, and links to other information here.

 

 

The Volcanic Alert Level system, used by GNS Science and GeoNet to communicate volcanic activity in New Zealand, will be changing on 1 July 2014. The six-stage system is changing to better meet the needs of users such as regional councils, tourism operators, Department of Conservation, Civil Aviation, Civil Defence organisations and the public. The new system can be accessed on the GeoNet website.

Changes in the new Volcanic Alert Level (VAL) system include having just one system for all volcanoes in New Zealand (previously there were two), restructuring the system so that there is an additional level for ‘moderate to heightened volcanic unrest’ (instead of just one level for all volcanic unrest), and adding in information about the most likely hazards that will be seen for each level of volcanic activity. The number of levels in the new system remains unchanged, and ranges from 0 (no volcanic unrest) to 5 (major volcanic eruption). No changes have been made to the international Aviation Colour Code system.

A Volcanic Alert Level system was first developed before the Ruapehu eruptions in 1995, and the same system has been used ever since. The Volcanic Alert Level has been used for eruptions at Ruapehu, White Island, Raoul Island and Tongariro (Te Maari). That system was reviewed between 2010 and 2014 as part of a research project that looked at improving the communication of information about volcanic activity. This research found that the system was perceived to be too complex, and that developments in volcano monitoring over the past 20 years have created an opportunity to improve the system. The improvements in volcano monitoring have come about through the GeoNet project (funded by EQC). Ways to make the system more understandable and useful were identified during the revision process, leading to the development of the ‘new’ Volcanic Alert Level system.

To find out more information on the new Volcanic Alert Level system, visit the GeoNet website. To learn about volcanic hazards visit GNS Science, and to find out what to do before, during and after volcanic activity, visit Get Ready Get Thru.

 

For further information;

contact Brad Scott

07 3748211

Volcano update   

New Zealand’s volcanoes have been very quiet for the last few months. Listed below are some of the highlights of recent activity for the volcanoes currently on Volcanic Alert Level 1.

White Island:

There were short lived eruptions at White Island on 8 and 11 October 2013 that affected the Main Crater floor. The major change since then has been the reestablishment of a hot crater lake.

Ruapehu:

The most recent eruption at Ruapehu was on 25 September 2007. The active crater is occupied by a warm crater lake, which is currently in a heating phase. As at 16 May 2014 the lake temperature was about 40 °C. The temperature of the Crater Lake at Ruapehu typically ranges from about 15 to 45 °C over 12-14 months.

Te Maari (Tongariro):

Eruptive activity occurred from Te Maari on 6 August and 21 November 2012. Since that time the active vent has remained very hot (over 400 °C on 2 May 2014) and continues to emit volcanic gases, especially CO2 and SO2. Steam and gas plumes are often present from the Te Maari vents.

FAQ’s

Q: Why change the old system?

A: One of the challenges of a Volcanic Alert Level System is to provide a system that can be used for a range of different volcanoes. The old system was used successfully through many eruptions, but user groups told us that the old system was too complex. The volcano monitoring scientists found that changes in volcanic unrest couldn’t be properly communicated using only one level.

Q: What happens if a volcano erupts around 1 July, when the Volcanic Alert Level system is due to change over to the new version?

A: The change will still go ahead on 1 July. This means that the Volcanic Alert Level for the erupting volcano will change on 1 July to match the new system. Information will be available on the GeoNet website.

Q: How did you come up with the new system?

A:  The old system was investigated as part of a PhD research project at Massey University. The research involved volcanologists at GNS Science, other scientists in New Zealand, and agencies that use the Volcanic Alert Level system. The purpose was to find out what worked well and what didn’t. The new system was developed from findings of the research project, in consultation with the Ministry of Civil Defence and Emergency Management, GNS Science and many other user groups.

Q: Will the new VAL system result in any noticeable differences in the way erupting volcanoes are managed?

A: The new VAL system is building on the old one, which we have lots of experience with. The new one is removing some of the former complexity and giving stronger guidance in dealing with volcanic unrest. We expect a smooth transition to the new system, which is designed to more accurately reflect the changing moods of New Zealand's volcanoes. This will lead to more efficient management of volcano emergencies and more clarity in messages about volcanic activity.

 Q: How do I find out if the Volcanic Alert Level changes?

A: When the Volcanic Alert Level is changed, GeoNet sends out information in a Volcanic Alert Bulletin. Volcano Alert Bulletins are distributed to responding agencies, the public and media, and on social media (Facebook and Twitter). The current levels are shown on the GeoNet webpages.

Q: What is the difference between ‘minor volcanic unrest’ and ‘moderate to heightened volcanic unrest’?

A: ‘Minor volcanic unrest’ means there are signs of life at the volcano, but the likelihood of an eruption is small. ‘Moderate to heightened volcanic unrest’ means that the signs of life at the volcano are stronger, and that there is a higher likelihood of an eruption developing. Being able to distinguish between these two levels of unrest due to advances in GeoNet volcano monitoring is an important part of the need for a change in the Volcanic Alert Level system.

Q: What is the difference between a minor, moderate and major volcanic eruption?

A: The differences relate to the magnitude of the eruption, and the area being impacted by the eruptions. A minor eruption will most likely create hazards near the eruption vent, such as the eruptions at White Island in 2013. A moderate eruption will most likely produce eruption hazards that will affect areas on the volcano – for example, the 1995-96 eruptions of Ruapehu.  A major eruption will most likely cause widespread hazards beyond the volcano. An example of a major eruption in New Zealand was the 1886 eruption at Tarawera. It is important to know that some eruptions will often have effects far from the volcano, even when caused by a minor eruption – these are ashfall, lahars and lava flows.

Q: What does it mean by “eruption hazards near vent”?

A: Minor volcanic eruptions are mainly hazardous in areas within a few hundred meters of the active vent. Typical hazards are from small explosions and will be ballistics (flying rocks); jets of rock, mud and steam; volcanic ash; and sometimes pyroclastic density currents (fast-moving hot ash and steam clouds). Hazard maps show the likely extent of volcanic hazards.

Q: What does it mean by “eruption hazards on and near volcano”?

A: Moderate volcanic eruptions are hazardous to areas near the vent, on the flanks of the volcano, and around the base of the volcano (i.e., within about 10 km of the vent). Typical hazards include explosions that produce ballistics (flying rocks), volcanic ash, pyroclastic density currents (fast-moving hot ash and steam clouds), lava flows and lahars. Some of these hazards may extend beyond the volcano. Hazard maps show the likely extent of volcanic hazards.

Q: What does it mean by “eruption hazards on and beyond volcano”?

A: Major volcanic eruptions are very large and will cause significant impacts near the vent and on the volcano, as well as areas further afield (i.e., more than 10 km from the vent). The most widespread and common hazard is volcanic ash, which can be carried tens to hundreds of kilometres downwind from the volcano. Other hazards like collapsing lava domes, landslides, pyroclastic density currents (fast-moving hot ash and steam clouds), lava flows and lahars may also extend a long way from the volcano. Hazard maps show the likely extent of volcanic hazards.

Q: What should I do before, during and after a volcanic eruption?

A: To find out what to do before, during and after a volcanic eruption, visit the Get Ready Get Thru website. You can also find information on the GNS Science website. 

Q: How can I find out more about New Zealand’s volcanoes, and volcanic hazards?

A: Click here to learn more about New Zealand’s volcanoes, and here for information on volcanic hazards (there is also a glossary of volcano terms). The GeoNet website shows the current level of activity at the volcanoes, and contains information on monitoring at our volcanoes, and about recent eruptions. There are also lesson plans for schools, and links to other information here.

 

Tuesday, 11 February 2014, 11:00 am - White Island/Whakaari activity update.

GNS scientists have recently visited White Island/Whakaari to make observations and continue to improve our volcano monitoring capabilities. The crater lake temperature is approximately 57 °C and its level continues to rise slowly. A new GPS system was installed to measure ground movements. The volcano remains in a generally elevated state of unrest.

During their visits to the island in early February, GNS Science staff measured the lake temperature (57°C) and that of fumarole F0 (147°C), on the southern part of ­the crater floor. These are similar to the last measurements in January. The lake level is still rising slowly, and has now drowned one of the fumaroles on the southern lake shore, causing occasional geysering in that area. No other substantial changes in activity in the lake area were observed compared with previous weeks.

A new permanent Global Positioning System (GPS) station­ was installed on the crater floor to strengthen the local volcano deformation monitoring. Volcanologist Brad Scott said: “Ground deformation at active volcanoes can be an indicator of pressure build-up at depth and general volcanic unrest. As one of multiple monitoring tools, GNS Science uses surveying techniques and GPS technology to monitor ground swelling and subsidence, to an accuracy of a few millimetres, at many of New Zealand’s volcanoes."

Over the past few weeks, the average daily sulphur dioxide gas flux has remained below 500 tonnes per day; this is lower than over the last few months and may be partly a result of the increasing lake level. GNS scientists also collected samples of rocks deposited during the October 2013 eruption; understanding how those eruptions occurred will help us to assess the future risk from the volcano.

White Island remains in a state of volcanic unrest. A range of eruptive activity can occur under these conditions and eruptions can start with little or no prior warning. Larger eruptions can eject mud and rocks and may impact the crater floor area. The Volcanic Alert Level remains at Level 1.

GNS Science is continuing to closely monitor the activity at White Island (and other New Zealand volcanoes) through the GeoNet project.

Want to learn more about volcano monitoring? See http://www.gns.cri.nz/Home/Learning/Science-Topics/Volcanoes/Monitoring-Our-Volcanoes

Nico Fournier
Duty Volcanologist 

Contact: Brad Scott

A new survey of the amount of carbon dioxide (CO2) soil gas flux and ground temperatures at Red Crater has shown little change since 2009. 

A new survey of the amount of carbon dioxide gas (CO2) coming out of the ground near Red Crater on Mt Tongariro has shown little change since an earlier survey in 2009. The temperature just below the ground surface is also little different from values measured in 2009. Together these new results show that the 2012 eruptions from the nearby Upper Te Maari Crater have had little lasting effect on the Red Crater area.

Our GeoNet gas chemists have several methods available for measuring the gas produced from our volcanoes. One of these is a soil gas flux meter. A round metal accumulation chamber is placed on the ground and the gas emitted from the soil is measured by an analyser carried in the chemist’s back-pack. Soil gas flux measurements can be used to track changes in gases coming from magma and the geothermal systems beneath volcanoes. Last week we repeated a carbon dioxide (CO2) soil gas and ground temperature survey at Red Crater, Tongariro.

The survey covered the same area that we covered in 2009. At each sampling site we measure the gas flux and then map this. From the measurements we can also calculate the total gas flux from the area. In 2009 we calculated a flux of 47 tons per day from the survey area. The result from the new survey in February 2014 is a flux of 39 tons per day. The difference is not considered significant.

 

We also measured the ground temperature at 10 cm depth everywhere we measured soil gas fluxes. There is again no significant difference in the ground temperatures between 2009 and 2014. Over the later part of the winter and this summer there have been some reports of trampers on the Tongariro Alpine Crossing getting a warm bottom when sitting at Red Crater to admire the view. Our new data show this area is not getting hotter.

 

Red Crater is one of several volcanic vents on Mt Tongariro. Eruptions are reported in 1855, 1886, 1897, 1926 and 1934. 

Wednesday, 22 January 2014, 9.00 am - White Island activity update; Volcanic Alert level remains at Level 1 (no change).

No further eruptive activity has occurred at White Island (Whakaari) since the moderate eruption on the evening of 11 October 2013. Volcano seismic activity remains at a low levels, while the gas flux has been at elevated levels. The Crater Lake continues to grow.

GNS Science staff have made several visits to the island in the last week to assess the status of the volcano, repair existing monitoring installations and evaluate new portable equipment. The volcano remains in an elevated state of unrest.

The water level of the Crater Lake continues to rise. Observations and photographs suggest it is about 5 m higher than late last year. Average daily sulphur dioxide gas flux has ranged from 133 to 924 tonnes per day. This remains elevated compared to levels before 2012 when daily averages were generally less than 300 tonnes per day.

Experiments with a recently-acquired thermal infra-red camera have enabled us to establish the lake surface temperature and the temperatures of several of the gas vents near the lava dome that was extruded in late 2012. This camera allows us to take images of the temperature of areas either from a helicopter or from the crater rim. The lake temperature ranged from 37 to 58 °C and averaged 51 to 52 °C. The temperature of the gas vents on the lava dome range from around 200 to 330 °C, and at one vent we have measured over 400 °C. These observations confirm hot volcanic gases are still passing through these vents.

Volcanologist Brad Scott said, “This new camera gives us some fantastic data on the heat coming from the volcano and allows us to build a better picture of the status of the activity.”

We have also tested a diode laser instrument to evaluate carbon monoxide and carbon dioxide gas emissions and a Fourier Transform Infra-Red (FTIR) spectrometer which can measure a very wide range of different gases. We are developing our capabilities in monitoring different gases so that we can better understand how the volcano behaves.

White Island remains in a state of volcanic unrest. A range of eruptive activity can occur under these conditions and eruptions can start with little or no prior warning. Larger eruptions can eject mud and rocks and may impact the crater floor area. The Volcanic Alert Level remains at Level 1. Aviation Colour Code remains Green.

GNS Science is continuing to closely monitor the activity at White Island (and other New Zealand volcanoes) through the GeoNet project.

Brad Scott
Duty Volcanologist

Contact: Brad Scott

 

23 December 2013, 3:30pm - Tongariro activity update; Volcanic Alert Level remains at Level 1 (no change); Aviation Colour Code remains Green (no change)

Tongariro volcano remains quiet. Te Maari has had no eruptive activity since an explosion on 21 November 2012 although there is still a small chance that an eruption could occur with little or no warning.

A few small earthquakes continue to be recorded on the northern flanks of Tongariro, occurring at a low rate of 2-3 per month. We are measuring sulphur dioxide fluxes of about 10-15 tonnes/day which is also a low level. The latest gas measurements were made last Friday.

On Friday GNS volcanologists also sampled the fumaroles on Te Maari that have been active since the eruptions in 2012. The main fumarole, which often provides strong steam plumes visible from Taupo, was emitting gases at over 400 °C.

GNS Science has not changed the Volcanic Alert Level or the Aviation Colour Code.

Through the GeoNet project, GNS Science continues to monitor Tongariro for any new earthquake activity or changes in volcanic gas concentrations, and keeps a close watch for any visible changes.

Background

Aviation Colour Codes are based on four colours and are intended for quick reference only in the international civil aviation community. Code Green indicates that a volcano has no eruptive activity.

The Volcanic Alert Level ranges from 0 to 5 and defines the current status at a volcano. Level 1 indicates volcanic unrest, with departures from background level.

Michael Rosenberg
Duty Volcanologist

Contact: Brad Scott

Monday, 23 December 2013, 3:30 pm - White Island activity update; Volcanic Alert Level remains at Level 1 and the Aviation Colour Code remains Green.

No further eruptive activity has occurred at White Island (Whakāri) since the moderate eruption on the evening of 11 October 2013. Seismic activity has remained at a low level since that eruption. Gas flux has been variable and the crater lake has re-established itself.

Average daily sulphur dioxide gas flux has ranged from 300 to over 1000 tonnes per day. This is elevated compared to levels before 2012 when daily averages were generally less than 300 tonnes per day.

There are now three webcams on White Island which enable us to keep a close eye on the crater lake and other areas of activity. The lake is now re-established and has drowned the vents that were active earlier this year.

Despite the seismic activity being at a low level, White Island remains in a state of volcanic unrest. A range of eruptive activity can occur under these conditions and eruptions can start with little or no prior warning. Larger eruptions can eject mud and rocks and may impact the crater floor area. The Volcanic Alert Level remains at Level 1.

GNS Science is continuing to closely monitor the activity at White Island (and other New Zealand volcanoes) through the GeoNet project.

Mike Rosenberg
Duty Volcanologist

Contact: Brad Scott

Keen volcano watchers may have noticed we have added a new web camera at White Island this week. The new camera has been installed on the western rim of the main crater, looking down on the Crater Lake and active vents.

From this site we get a near birds-eye view of where all the action is going on. Unfortunately this is also where all the steam and gas comes from, so often the view may be obscured too. As the new camera is in fact ‘two’ cameras, a standard daylight camera and a specialised ‘low light night’ camera, we will have images at night as well.

This camera install has come with a series of challenges for the GeoNet technical team: the site is very exposed and has taken two attempts to complete the install. In parallel with the physical install has been the challenge of reconfiguring the data network on the island and links back to the mainland. We have now established three data links off the island and have been able to connect all our equipment through WiFi links. These include the two seismographs with acoustic sensors, a GPS, tiltmeter and gravity meter, the two existing cameras, the two miniDOAS spectrometers and the experimental data logger at ‘Fumarole 0’.

An important part of volcano monitoring is visual observations, and a great way to achieve this is by the use of remote cameras. Advances in camera technology and, more importantly in the case of White Island, the upgrade of the data links from the island, are allowing us to bring back more data. As with all of our remote camera installs the local conditions are going to dictate how many useful images we get from the site. The steam and gas plume from the active vents does tend to frequently rise up the western crater wall which will obscure the view from time to time.

Monday, 4 November 2013, 11:30 am - White Island activity update; Volcanic Alert Level remains at Level 1 and the Aviation Colour Code is lowered to Green.

No further eruptive activity has occurred at White Island (Whakāri) since the moderate eruption on the evening of 11 October 2013. Seismic activity and gas flux from the volcano have been at a low level since the eruption. The Aviation Colour Code has been lowered from Yellow to Green.

The potential impact of volcanic activity on aircraft has decreased and GNS scientists have lowered the Aviation Colour Code from Yellow to Green. The Aviation Colour Codes are based on four colours and are intended for quick reference only in the international civil aviation community.

Despite the seismic activity and gas flux from the volcano being at a low level, White Island remains in a state of volcanic unrest with instability in the volcano-hydrothermal system. A range of eruptive activity can occur under these conditions. Eruptive activity can be expected with no prior warning. The larger eruptions can eject mud and rocks and may impact the crater floor area. The Volcanic Alert Level remains at Level 1.

GNS Science is continuing to closely monitor the activity at White Island (and other New Zealand volcanoes) through the GeoNet project.

Nico Fournier
Duty Volcanologist

Contact: Nico Fournier

Monday, 21 October 2013, 2:30 pm - White Island activity update; Volcanic Alert Level lowered to Level 1 and the Aviation Colour Code remains at Yellow.

No further eruptive activity has occurred at White Island (Whakaari) since the moderate eruption on the evening of 11 October. Volcano seismic activity has declined but remains variable. Gas flux remains high. Volcanic unrest continues at White Island. The Volcanic Alert Level has been lowered from Level 2 to Level 1. Aviation Colour Code remains at Yellow.

Since the moderate eruption on the evening of 11 October no further eruptions have been detected at White Island. A visit to examine and sample the effects of the eruption and repair damaged equipment has confirmed the entire Main Crater floor was affected. Ejecta extended to over 350 m from the active vent and a wet volcanic surge cloud enveloped the Main Crater, depositing a muddy layer.

Volcanic tremor levels decreased after the eruption on 11 October and have remained at variable levels since then. A successful gas flight was made on 17 October. The SO2 flux was 450 tonnes per day, CO2 1140 tonnes per day and H2S 12 tonnes per day. The SO2 and H2S flux is little changed, CO2 has decreased from the previous measurements on 23 August. The gas data suggests that there is continuing degasing of a shallow body of magma (molten material). The daily SO2 measurements from data logging equipment on the island show the SO2 flux has ranged from 408 to 1400 tonnes per day over the last week and the average flux remains elevated.

White Island remains in a state of volcanic unrest with instability in the volcano-hydrothermal system. A range of eruptive activity can occur under these conditions with little or no prior warning. The larger eruptions can eject mud and rocks and may impact the crater floor area.

GNS Science is continuing to closely monitor the activity at White Island (and other New Zealand volcanoes) through the GeoNet project, and will provide more information as it becomes available.

Brad Scott
Duty Volcanologist

Contact: Brad Scott

Monday, 14 October 2013, 1:45pm - White Island activity update;  Volcanic Alert Level remains at Level 2 and the Aviation Colour Code is lowered from Orange to Yellow.

Volcanic unrest continues at White Island. Following the moderate eruption that occurred on the evening of Friday 11 October the tremor level has declined, although the potential for further eruptions with little or no warning remains. The Aviation Colour Code has been lowered from Orange to Yellow but the Volcanic Alert Level remains at 2.

Volcanic tremor levels gradually decreased after the eruption on Friday and are now at levels equivalent to the middle of last week. Measurements of sulphur dioxide gas emissions from the last week show an increase in gas levels towards the end of the week with a maximum of over 1,000 tonnes/day of sulphur dioxide measured on 11 October. This is one of the highest values that we have measured since June last year.

Video compilation from the web camera on the Crater Floor shows the activity on Friday evening with a rapidly expanding ash cloud moving towards the camera. The video clip can be seen at: http://youtu.be/7YuOFddVGwc. Note times in video clips are in UTC (Co-ordinated Universal Time, 13 hours behind local time).

The accompanying photos from the crater rim camera show the effects of the eruption with one image from the day before the eruption and one image from the morning afterwards. Note how the dark grey mud coats the crater floor and crater walls. The eruption was larger than previous events over the last year, in terms of the area impacted by mud, and would have been life threatening if there had been people on the island.

A range of eruptive activity has occurred over the last 15 months, with more frequent events in the last couple of weeks. Eruptive activity can be expected with no prior warning. The larger eruptions can eject mud and rocks and may impact the crater floor area to which visitors have access.

GNS Science is continuing to closely monitor the activity at White Island (and other New Zealand volcanoes) through the GeoNet project, and will provide more information as it becomes available.

Gill Jolly
Duty Volcanologist

Contact: Brad Scott

Saturday, 12 October 2013, 12:00pm - White Island activity update;  Volcanic Alert Level is raised to Level 2 and the Aviation Colour Code is raised from Yellow to Orange.

A moderate explosive eruption occurred at White Island (Whakāri) at approximately 8:09pm NZDT last night. The eruption lasted about 1 minute based on data from acoustic and seismic sensors, and was confirmed by subsequent analysis of web camera images during daylight hours. As a consequence of this activity the Volcanic Alert Level is now raised to Level 2 and the Aviation Colour Code to Orange.

Observations from the web cameras show an explosive eruption producing an ash cloud column that expanded across the Main Crater floor. New mud deposited on the crater floor is evident in the web camera images from the crater rim this morning. The present activity is a continuation of the unrest observed at White Island for the past 15 months and hazardous eruptions of this type may occur with no warning. This eruption is larger than recent events and would have been life threatening to people on the island.

We will provide more information as it becomes available.

Arthur Jolly
Duty Volcanologist

Contact: Brad Scott


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