Tag Archives: Volcano

Yadnya Kasada Festival


Since the dawn of man people have seen volcanoes as expressions of the rage of the God’s, punishments for poor behaviour on Earth. This was really brought home to me while working on Masaya last year. A huge cross now stands where, mainly women and children, were thrown in to the lava lake below as a sacrifice to the gods to spare the towns on the volcanoes flanks. Luckily human sacrifice is a thing of distant memories in most cultures but this does not mean people do not still worship at volcanoes.

Hindu devotees climb up to the crater of Mount Bromo.

The Tenggerese people are an ethnic minority in eastern Java who claim to be the descendants of the Majapahit princes. Predomintaly Hindu they have also incorporated many Buddhist and Animis elements. Yesterday marked the 14th day of their yearly festival Yadnya Kasada. Thousands flocked to the crater edge of Bromo to ask for blessing from the main deity Hyang Widi Wasa and Mahadeva, the God of the Mountain (Mount Semeru) by presenting annual offerings of rice, fruit, vegetables, flowers, livestock and other local produce

A Hindu devotee praysduring the Yadnya Kasada festival.

On December 5th last year Bromo’s PVMBG raised the volcano’s alert status to “siaga” (alert), or 3 on a scale of 1-4, it has remained around this till now with ash emissions continuing at fluctuating levels. Currently an ash column towers just under 1000 metres above the main vent, a sulphurous order lingers in the air. None of this however swayed the visitors eager for blessings. Many who ventured right up to the crater rim can be seen to wear rags around their faces to protect from the fumes, no effort was made to prevent people from entering the area.
The days of virgin girls meeting a fiery death may be long gone and now mainly goats and chickens lose there lives, but it is still shows the connections and respect people have for our planet and its power. This festival is not the only one world-wide which has a similar theme and I feel no matter the scientific findings about the inner working of our planet it will never deter such worship.







Figure 1; http://www.usatoday.com/picture-gallery/news/2016/07/21/the-yadnya-kasada-festival-in-indonesia/87385912/

Figure 2; http://www.usatoday.com/picture-gallery/news/2016/07/21/the-yadnya-kasada-festival-in-indonesia/87385912/

Figure 3; http://yourindonesia.arah.com/article/6681/upacara-yadnya-kasada-jadi-wisata-budaya-di-bromo.html

Figure 4; http://www.straitstimes.com/multimedia/photos/in-pictures-the-yadnya-kasada-festival-in-indonesia


Today in Geological History; June 15th – Mount Pinatubo 1991


Figure .1 Mount Pinatubo 1991

Before the eruption in the early 90’s, Pinatubo was a rather unassuming mountain on the island of Luzon, Philippines. Standing only 2000 ft above surrounding peaks, it was almost obscured from vision. It’s flanks covered in lush green forest, without an eruption in memorable history, people never saw it as a threat.  This change in June 1991 when it produced the second largest eruption of the 20th century (after Novarupta 1912).

Figure 2. Damage from the earthquake in 1990.

In 1990, on July 16th a magnitude 7.8 rocked the island of Luzon. A strike-slip along the Philippine Fault System it caused a surface rupture oer 125 km long. Killing  over a thousand people it became the deadliest earthquake in Philippine history but may also have been the start of something much greater, geologists have long been convinced that it is linked to Pinatubo’s activity the following year. However it has never been proven if this earthquake stirred the sleeping volcano or if the reawakening caused the quake. For a few weeks after locals reported steam coming from Pinatubo, but when it was visited by PHILVOLC’s scientists there was only landslide evidence and not emissions.

Seismicity kicked off activity again on March 15th 1991. The north-west side of the volcano felt a swarm of tremors increasing in intensity over the next two weeks. On April 2nd a 1.5 km fissure opened along the summit with phreatic explosions dusting the local area in ash. seismicity continued to increase causing volcanologist to rush to its flanks to place monitoring equipment they had never thought to place while the mountain lay in slumber. The volcanoes eruptive history had very been studied before and they were surprise to learn it had large eruptions as recent as roughly 500, 3500 and 5500 years ago. On April 7th the first formal evacuations took place. With the Clark Air base just 14 km from Pinatubo the USGS aided PHILVOLCS in setting up 3 zones the first, a 10 km radius from the summit was the initial area to be designated unsafe and people were quickly evacuated to safety. Further zones from 10-20 km and 20-40 km were deemed safe for now but people were told to be alert to the possibility of evacuation if the mountain showed any sign of getting worse.

Figure 3.

Activity stepped up in May with sulfur dioxide emissions rocketing from roughly 500 t p/d at the beginning of the month to over 5000 t p/d by May 28th. At this point emission slightly decreased and inflation began to increase rapidly leading many to believe pressure was building with the magma chamber.

On June 3rd the first lava was noticed signalling that a magmatic phase of the eruption had begun which eased some people’s mind as activity seemed relatively effusive. The first large explosion cam four days later on June 7th. An eruption column towered 7 km above the summit prompting the second wave of evacuations with people in the 10-20 km zone being prompted to leave their homes. A lava dome began to grow dramatically in the next few days reaching in excess of 600 ft wide. Activity seemed pretty constant at a low-level until 03:41 on June 12th when a new, more violent phase of eruptions began. As explosions intensified over the next few hours the eruption column grew to over 19 km. Pyroclastic flows surged as 4km from the summit in some valleys. Ash and tephra rained down on the surrounding area as the intense explosions lasted over  . The final wave of evacuations was called for on the morning of June 13th as a small but intense earthquake swarm saw in a third phase in the eruption.

Figure 4. On of the most iconic images from the 1991 eruption.

People as far as 40 km away, and even further if possible, were urged to leave the area as quickly and calmly as possibly as Pinatubo showed no signs of slowly down its activity. The column peaked again, this time over 24 km high. Several more large explosions were recorded for the next 24 hours including one at lunch time on the 14th with saw another 21 km eruption column and more pyroclastic flows obscuring the view of the flanks.

From midday on June 15th the eruption reached its most climatic point. By 2.30 pm on the June 15th readings stopped being received from seismometers and other remote censoring equipment which the USGS had placed at Clark Air base indicating the area had been over some by the pyroclastic material still being ejected at a terrifying rate. An ash cloud covered an area greater than 125,000 km2 bringing near total darkness to much of the island of Luzon and ashfall was recorded as far as neighbouring countries of Cambodia, Malaysia and Vietnam. By 10.30pm that night all fell quiet and Pinatubo’s fury seemed to be over.

Figure 5. Mapping the spread of the SO2 released by Pinatubo.

The VEI 6 eruption spat out over 10,000,000,000 tonnes of material and a whopping 17,000,000 tonnes of sulphur dioxide. It was the later which signed Pinatubo’s fate in people’s minds as the SO2 emitted quickly covered the globe causing the mean global temperatures to drop by 0.5°C for the following two years. Sulphur dioxide in the atmosphere reflects the Sun’s radiation back in to space meaning the Earth’s surface received up to 10% less sunlight in the following year. It also meant an increase in ozone damage, with the hole above the Antarctic being at the largest it had ever been.

An estimated 847 people lost their lives (many from collapsing buildings under the weight of the ashfall),but problems continued past initial fatalities in the aftermath. Over 2.1 million people have believed to have been affected by the disaster. Agriculture was severely effected both my ash fall and then following effects of the climate. Lahars plagued the region for years after with each heavy rain fall. It is often put by the end of 1992 the eruption and resulting lahars caused the country losses in excess of 400 million US dollars.

Despite this, the events of 1991 are often hailed a volcanological triumph with quick responses, prediction and evacuation believed to have saved the lives of thousands. It enabled us to gain an insight to volcanic impacts on climate and how we monitor the risks.

Figure 1. http://www.slate.com/articles/life/welltraveled/features/2012/tempting_fate_in_the_philippines_/dennis_rodman_s_dad_and_the_eruption_of_mount_pinatubo_.html

Figure 2. http://xuwenewegu.webatu.com/earthquake-in-philippines-july-25-2011.php

Figure 3. http://www.coolgeography.co.uk/GCSE/AQA/Restless%20Earth/Volcanoes/Mount%20Pinatubo.htm

Figure 4. https://www.uclm.es/profesorado/egcardenas/pa.htm

Figure 5. http://earthobservatory.nasa.gov/IOTD/view.php?id=1510

Today in Geological History; June 3rd – The 25th Anniversary of Unzen


Today marks the 25th anniversary of the pyroclastic flow from Mount Unzen which claimed the lives of 43 people.

Mount Unzen

Mount Unzen is actually several over lapping volcanoes on Japan’s island of Kyushu. It was the cause of Japan’s largest ever volcanic disaster in 1792 when a lava domed collapsed and caused a mega tsunami which killed nearly 15,000 people. After this even the volcano lay silent until beginning to stir in 1989.

Seismic swarms began in the November of 89 about 10 km west of the summit and gradually migrated eastward until the first phreatic eruption a full year later in November 1990. By May 20th 1991 fresh lava began to flow from the highly inflated summit area prompting the evacuation of almost 12,000 locals.

volcano-unzenThe threat of another eruption to the scale of 1792 brought journalists and scientists alike flocking to the surrounding area to monitor the activity of Unzen and its potential threat. Sadly this curiosity resulted in the deaths of 43 when on June 3rd activity peaked due to a possible lava dome collapse. This sent a huge pyroclastic flow surging down its flanks and funnelled in to a valley point in the direction where volcanologists and journalists had set up a base at what was thought to be a safe distance, over 4.5 km, from the summit.

Activity continued well in to 1995 and over 10,000 pyroclastic flows were recorded over this period. By the end of the eruption a new lava dome was in place 1.2 by 8 km wide. Its volume was approximated at 0.1 cubic km.  In total, about 0.21 cubic km of plagioclase-phyric dacite magma was erupted over the course of the eruption at peak effusive rates of 7 cubic metres per second in 1991. Over 2000 buildings were destroyed by these flows in Shimabara City alone. Matters were further complicated between August 1992 and July 1993 when heavy rains caused multiple lahars destroying a further 1300 homes along the Mizunashi and Nakao Rivers, requiring the sudden evacuation of several thousand residents.

Mount Unzen has been placed on the official decade volcano list and is one of Japan’s most highly monitored areas.

Maurice and Katia Krafft

The Krafft’s were French volcanologists and soul mates who met at the University of Strasbourg. Their love for volcanology almost reviled their love for each other. The specialized in documenting eruptions as best and often as close as possible, their end was almost inevitable.

Their most famed contribution was the documentation of Nevado del Ruiz which when shown to the Phillipine president Corazon Aquino who was then convinced to evacuate the area surrounding Mount Pinatubo before its catastrophic 1991 eruption almost certainly saving hundreds if not thousands of lives. 

Over a 20 year period, when volcanology was still a relativity young science, the married couple documented hundred of eruptions. They fillmed over 300 hours of footage, took thousands of photos and published multiple books.

While in the Philippines during Pinatubo’s early stages, Maurice was interviewed by a local news agency where he told the journalist  “I am never afraid, because I have seen so much eruptions in 23 years that even if I die tomorrow I don’t care.” From here they flew out to Japan where activity was picking up at Unzen. The pair perished together when they were overcome by the pyroclastic flow on June 3rd.

Harry Glicken

Man wearing a coat and hat and holding a pad of paper sits on a rock , with a lake and several mountains visible in the backgroundHarry was an American volcanologist who although was based at USGS was funded by outside organisations. He specialised in volcanic debris flows and was closely involved with research on St Helens with his doctoral thesis ‘Rockslide-debris Avalanche of May 18, 1980, Mount St. Helens Volcano, Washington‘ being recognised as a leading paper on the event.

Glicken cheated death on St Helens as he was meant to be the volcanologist on duty May 18th however swapped with his then mentor David Johnston who was killed by the blast.

Figure 1; http://raredelights.com/top-28-worlds-important-volcanoes/mount-unzen-in-japan/

Figure 2; https://curiousmatters.wordpress.com/2014/05/23/curious-facts-31-of-the-strongest-volcanoes-known-to-man/

Figure 3; https://en.wikipedia.org/wiki/Mount_Unzen

Figure 4; https://volcanogeek.wordpress.com/2011/09/20/maurice-and-katia-a-love-story/

Figure 5; https://en.wikipedia.org/wiki/Harry_Glicken

Figure 6; https://www.youtube.com/watch?v=Cvjwt9nnwXY





Sinabung Claims More Lives


Sadly I awoke this morning to the news Mount Sinabung in Northern Sumatra, Indonesia had claimed the lives of three farmers working in the fields by the Gembar Village. This figure has since risen to 7 and is feared to continue to rise with several more critically injured and the Red Cross and army looking for further victims.

Mount Sinabung has been in a near constant state of eruption since late 2013. Pyroclastic flows sweep down its flanks on a regular basis which has lead to 4 km exclusion zone being enforced around the summit.  On February 1st 2014 people were killed by one such pyroclastic flows.

About 10,000 people have been displaced by activity at the volcano which has been on the highest state of alert for well over a year. Sadly the volcano is positioned in a relatively poor and over populated area of the world, many people have little choice but to continue to farm on the volcanoes fertile flanks. Officials have struggled to keep the people to stick the ‘red’ exclusion zones and it is unclear how many people were on the mountain at the time of the recent activity.

Head of the National Disaster Mitigation Agency (BNPB) Willem Rampangilei has instructed Karo Regent to take quick measures to vacate the red zones (Gamber village, Simpang Empat district and Karo Regency) but they know that this is easier said then done. The pyroclastic flows caused by partial collapses of the growing lava dome occurred in a series at 14:28, 15:08 and 16:39 local time on Saturday. Rescue attempts went through the night and in to Sunday morning. An ash column remained for hours, towering over the area darkening the skys and hampering the search operation.

The pyroclastic flow captured here to the left happened only a week ago on May 16th showing the power and regularity of such activity. On May 9th a lahar swept through  Kutambaru near the Lau Barus River killing 1 and leaving one person still missing now also presumed dead.

Sinabung lay silently for nearly 400 year until springing back to life back in 2010. It has now killed at least 25 people since its rousing. Volcanism on the island of Sumatra is caused by the subduction of the Indo-Australian plate beneath the Eurasian plate along the Sunda Arc which creates the andesitic-dacitic composition magmas which are prone to such explosive activity. Sinabung sits just 25 miles north-east of the Toba Super Volcano caused by the same tectonic motion.


Figures 1 and 2; posted to Facebook by SkyAlert.

Figure 3; http://www.volcanodiscovery.com/sinabung/news.html


Kyushu Earthquake, Mt Aso and the Relationship between Volcanoes and Earthquakes.


In the past week the Japanese Island of Kysushu has be ravaged by earthquakes.

2016-04-16Japan is a highly seismic area with noticeable quakes in some areas occurring nearly daily.  But things began to escalate for the Kyushu region on Thursday night when a magnitude 6.5 quake brought several buildings down. As rescue efforts began the region had two more huge after shocks during the night, one over Mg 6 and the other > Mg 5. By midday Friday the death toll stood at 9 with over 800 injured and although the aftershocks kept coming many >Mg 4 people were still being pulled from the rubble. Sadly these events were quite possibly a precursor to something larger.

At 01.25 local time (15.25 GMT) a Mg 7.3 struck just north of Kumamoto just kilometers from the large earthquakes which had already occurred. Much of the seismicity in the Kyushu region is related to the subduction of the Philippine Sea plate at great depth. However this series of earthquakes have occurred at very shallow depths several hundred kilometers northwest of the Ryukyu Trench. They have been cause by strike-slip faulting within the Eurasian plate.

Quake damaged houses in Kumamoto, Japan (16 April 2016)So far 22 more people have been reported dead but this is expected to rise in the coming days with at least 80 people known to betrapped in rubble. 11 of which are trapped in a Tokai university apartment in the town of Minami Aso.


The shallowness of the earthquakes means damage to the surface is high and it is not just collapsing building which are a hazard. People have fled the area down stream of a dam which collapsed soon after the earthquake. Landslides in the area have taken out roads and power lines and with heavy rain anticipated over the coming days JMA have advised mudslides will be a huge problem for rescuers.







The seismic problems of Kyushu may have also set in motion another geohazard in the form of Mt Aso. Yesterday one of my favorite volcanology bloggers Eric Klemetti tweeted “Quite a few volcanoes on Kyushu and these earthquakes have been centered near Unzen, Aso, Kirishima. This is NOT to say these earthquakes will trigger any eruptions, but could be worth watching over the next year.” Several hours late JMA reported a small scale eruption at Aso. Smoke plumes have migrated 100 meters above the summit and it is not yet clear if the activity is magmatic (caused by movement of magma towards the surface) or phreatic (steam explosion caused by heating of groundwater).

Eruptions and earthquakes do not always come hand in hand but each one can contribute to the other or not at all depending on the circumstances. One indication a volcano is about to erupt is volcanic tremors; these low frequency earthquakes are usually caused by the migration of magma or changes to magma chamber. Although they are rarely higher than a magnitude 4. On the other side large earth quakes can cause faulting in bed rock which allows magma to exploit a new weakness and find a path to the surface it previously could not intrude on. The same can happen for ground water with faulting caused by a quake allowing it to seep in to geothermal areas it previously did not have access to due to the impermeability of the rock. When earthquakes hit volcanic regions volcano observatories always keep a closer eye on vulnerable or highly active volcanoes as a precaution but it is not always needed.


The Aso Caldera complex has one of the world’s largest calderas. It is comprised of a 25 km north-south by 18 km east-west Caldera and a central cone group comprised of Mt. Neko, Mt. Taka, Mt. Naka, Mt. Eboshi, and Mt. Kishima. Mt Naka where the eruption has just taken place is the most active with its most recent eruption taking place last October. Although much of Aso’s activity in the past century has been relatively small it has had a violent history with at least 4 VEI 7 events in the past 300,000 years.

It’s is not clear whether the earthquakes in the past few days did trigger the current current eruption but JMA are keeping a close eye on the situation and I will update this page as I know more.



Figure 1. http://earthquake.usgs.gov/earthquakes/map/

Figure 2; http://www.bbc.co.uk/news/world-asia-36061657

Figure 3; http://www.independent.co.uk/news/world/asia/japan-earthquakes-dozens-reported-dead-injured-second-quake-two-days-a6986931.html

Figure 4; http://mashable.com/2016/04/15/japan-earthquake-landslide-photos/

Today in Geological History; Feb 19th – Huaynaputina 1600


Today 416 years ago South America experienced its most explosive eruption in historical times. The unassuming Huaynaputina volcano sits in southern Peru just 26 km of Ubinas, the countries most active volcano. Unlike its 5672 m neighbour, Huaynaputina has no distinct topographic elevation and lays inside a 2.5 km crater leading many to believe it was just a mountain caused by other forces. Laying in the Andean Volcanic Belt where the Nazca Plate subducts under the western edge of the South American Plate it is situated on the rim of the Rio Tambo canyon further camouflaging it to the untrained eye.

The sleeping giants last eruption was in February 1600. Reaching an impressive VEI 6, it was the biggest eruption of the past 2000 years.

Details of the eruption were captured beautifully by Fray Antonio Vazquez de Espinosa a Spanish monk travelling through Central and South America at the time. Days before the eruption booming noises were heard from the vicinity and steam was seen seeping from the volcano. Locals began to panic, preparing young girls for sacrifice to appease Supay the god of death who people believed was angry at them and causing the mountains behaviour. February 15th marked a strong increase in activity with tremors becoming stronger and more frequent, many began to leave the area fearing something bigger was coming.

At roughly 5 P.M. on February 19th, Huaynaputina erupted violently catapulting ash high in to the stratosphere. Pyroclastic flows sped down all sides of the volcano, to the south mixing with the waters of the Rio Tambo river causing devastating lahars.  Within just 24 hours, Arequipa was covered with 25 centimetres (10 in) of ash. Ashfall was reported 250–500 kilometres (160–310 mi) away, throughout southern Peru and in what is now northern Chile and western Bolivia. It is thought that more than 1500 people were killed by the eruption its self although with little record of populations at the time the figure varies between sources. 10 villages were completely buried by ash and regional agricultural economies took 150 years to recover fully.

It was not just South America which was effected by the eruption. Ice cores recorded a spike in acidity at the time indicating a phenomenal amount of sulphur dioxide was released. Effects on the climate right around the Northern Hemisphere (Southern Hemispheric records are less complete), leading to 1601 being the coldest year in six centuries, leading to one of the worst famines ever recorded in Russia. In Estonia, Switzerland and Latvia, there were bitterly cold winters in 1600–1602 leading the deaths of hundreds; in 1601 in France, the wine harvest came late and in Germany production of wine collapsed completely. In Japan, Lake Suwa had one of its earliest freezings in 500 years and even China recorded peach trees blooming late.

An eruption of this scale in the populated Peru would be devastating so close watch is kept on Huaynaputina and its more active neighbours.


Figure 1; https://commons.wikimedia.org/wiki/File:Huaynaputina.jpg

Figure 2; https://volcanohotspot.wordpress.com/2015/04/12/volcanoes-of-peru-3-huaynaputina-catastrophe-in-1600/


Lake Taupo


For years a major thing on my bucket list was to swim in a crater lake, which as the name suggests is a body of water formed in a volcanic crater or caldera. Luckily I got to tick this one of when I visited Nicaragua last year and swam in the blissfully warm Apoyo Lagoon, but of course this only appealed to my addictive nature and made me dream about going one better…how about a crater lake formed by a super eruption. When my friend told me she was off travelling for a few months and her first port of call would be New Zealand, I decided she could live my dream for me on this one and I straight away advised her to head to Lake Taupo. Of course to any one without local knowledge or a familiarity with historic eruptions, this would not be of any significance. To be honest neither would me telling them I want to go swim in a random lake in New Zealand. So I decide to write a peace on one of the largest eruptions in the past 70,000 years to explain just why it is so important.

With a surface area of 616 square kilometres (238 sq mi), it is the largest lake by surface area in New Zealand and the second largest freshwater lake in Oceania. Now it’s a popular tourist destination, an area of true natural beauty, but this tranquil lake was born from a violent even which occurred roughly 26,000 years ago.

Volcanoes graphicThe Taupo volcanic zones spans a hug area in North Island 350 kilometres (217 mi) long by 50 kilometres (31 mi) wide. Mount Ruapehu stands 2797 high and marks its southern limits, while a submarine volcano, Whakatane volcano, 85 kilometres (53 mi) beyond White Island is considered it’s north-eastern.  Several volcanoes in the zone are still very active with Ruapehu and Tarawera causing New Zealand’s most deadly eruptions in the past few centuries (both events killing around 150 people each). None of these small events come close to the Taupo volcano itself after which the zone is named. The zone is caused by east-west rifting within plate the at a rate of 8mm per year, slowly pulling the Northern Island apart.


Taupo’s last eruption is referred to as the Hatepe eruption and has be dated at roughly 180 AD was a VEI 7 making it one of the largest in the past 5,000 years. It coincided with reports as far away as Rome and Northern China of brilliant red skyies and disruption to climate for several years. Haptepe spewed more material in to atmosphere than several of the largest eruptions of this century combined, but still it was nothing compared to the event which form the Taupo caldera and in turn Lake Taupo; the Oruanui eruption.

The Unit as the level of the volcanologists feet is an exposure of an unwelded pyroclastic flow deposit from the Oruanui eruption. The light- coloured air fall pumice are from varying eruptions between Oruanui and the uppermost layer of deposits which were laid by the Hatepe eruption.

Its hard to imagine what the Northen Island looked like before the Oruanui eruption 26,500 years ago with out the gapping hole that is Lake Taupo at its heart. The eruption released an estimated total of 1,170 km3 (280 cu mi) of material, a VEI 8 eruption making it the largest eruption of the past 70,000 years. It effected climate world wide for decades, many people saying it had a helping hand in the last glacial maximum. The effects are hard to comprehend when the largest volcanic eruption in human times was only a fraction of the size.

The eruption caused the Taupo magma chamber to collapse on its self creating the vast caldera which today Lake Taupo occupies just over two thirds of. Ash fall deposits from the eruption have been documented over 1000 km on Chatham Island showing the intensity of the blast. An event like this would decimate modern day New Zealand quiet possibly leaving no survivors on the Northern Island if not enough warning was given. Luckily though all is peaceful and scerene on the shores of the Great Lake and no threat appears to be imminent. That said Taupo still shows us gentle signs of the power beneath with its Craters of the Moon tourist attraction filled with steam vents and mud pools as well as numerous hot springs.

When people ask me why I study volcanology when the risk is “minimal” to human life in comparison to say earthquakes or flooding, this is a prime example which shows how little people know about what our planet is capable of. So Ginge, I hope you enjoy your trip and now understand a little more why Taupo is one part of your adventure I sincerely wish I was there!


Figure 1; http://www.waikatoregion.govt.nz/Services/Regional-services/Regional-hazards-and-emergency-management/Lake-Taupo-Erosion-and-Flood-Strategy/

Figure 2; http://www.gns.cri.nz/Home/Learning/Science-Topics/Volcanoes/New-Zealand-Volcanoes

Figure 3; http://volcano.si.edu/volcano.cfm?vn=241070