WHAT IS HAPPENING AT WHITE ISLAND VOLCANO??? New Zealand/Kermadec & South Pacific QUAKE/VOLCANO WATCH

Alert raised on Level 2 for New Zealand’s White Island volcano

[link to thewatchers.adorraeli.com]

image
A close up view of the dome. The dome is made of thick, relatively cool and congealed lava and has prominent spines. The dome is about 20 – 30 metres across. In the foreground is a small, cold lake. (Credit: Brad Scott/GeoNet)
[link to thewatchers.adorraeli.com]

Experts are concerned if lava dome should grow, because it can be accompanied by explosive eruptions and could impact people on the island.

image
White Island showing a wide view of the active crater area. The lava dome is at the base of the prominent steam plume on the right side. The larger steam plume on the left side comes from a hot lake. (Credit: Brad Scott/GeoNet)
[link to thewatchers.adorraeli.com]

all these last few listed 3.0+ mag quakes have occurred between tauranga and kermadec

4.3 03:26:05 Thu 13 Dec 2012 Depth: 215.2 km

3.6 00:52:37 Thu 13 Dec 2012 Depth: 410.9 km

3.8 23:12:35 Wed 12 Dec 2012 Depth: 231.4 km

3.1 11:16:00 Wed 12 Dec 2012 Depth: 264.0 km

4.1 05:28:06 Wed 12 Dec 2012 Depth: 170.1 km

3.7 02:46:16 Wed 12 Dec 2012 Depth: 337.5 km

map to see locations
[link to quakemap.co.nz]

things are continuing to build up at kermadec and rarotonga too

[link to www.geonet.org.nz]

[link to earthquake.usgs.gov]

Magma Origin and Evolution of White Island (Whakaari) Volcano, Bay of Plenty, New Zealand

White Island is an active composite stratovolcano in the Bay of Plenty, New Zealand, that comprises many small volume (<0·1 km3) andesite–dacite lava flows and pyroclastic deposits with phenocryst contents of &#8764;15–44%. Minor high-Mg basaltic andesite explosive eruptions, such as those of 1976–1992, may have occurred at intervals throughout the history of White Island, but are rarely preserved. These alternate with major episodes of andesite–dacite lava extrusion. The high-Mg magmas form by hydrous melting of mantle, metasomatized by fluids from the dehydrating slab at the slab–mantle wedge interface, that rise rapidly to shallow magma chambers (2–7 km?) where limited mixing and contamination occurs before eruption. Some of this magma remains in the magma chamber where it interacts with the crystal mush, from which it inherits phenocrysts, to form so-called ‘dirty’ lavas. Total phenocryst content of these lavas is correspondingly higher. As more magma is intruded into the chamber, the heat flux will increase and melt fraction will eventually rise to the surface to form high-silica andesite–dacite magma (‘clean’ lavas) with fewer inherited phenocrysts. Similar multi-magma chamber plumbing systems, with complex evolution involving fractionation and contamination, probably occur in most andesite–dacite arc volcanoes.

[link to petrology.oxfordjournals.org]

New Zealand lies along an obliquely convergent plate boundary between the Pacific and Australian plates. East of the North Island, the Pacific Plate is being subducted westwards under the Australian Plate at a rate of &#8764;50 mm/yr to form the Taupo–Hikurangi arc–trench system. Volcanic activity is now concentrated in the Taupo Volcanic Zone (TVZ), the youngest expression of 22 Ma Cenozoic continental margin arc volcanism in the North Island of New Zealand (Cole, 1990). TVZ (Fig. 1 inset) is at the southern end of the 2800 km Tonga–Kermadec–Taupo volcanic arc system and the Lau Basin–Havre Trough–Ngatoro Basin back-arc basin system. Southern Havre Trough and TVZ are offset sinistrally by 40–50 km and Wright (1992) believes the offset to be accommodated by a series of dextrally oblique and en-echelon bookshelf faults. The southwestern limit of this fault system is placed <20 km north of White Island and has NW–SE orientation (Fig. 1 inset).

Fig. 1.
Map of the Bay of Plenty. Offshore faults and main structural elements are from Wright (1992). VR, Volckner Rocks. Inset map of Taupo Volcanic Zone shows location of White Island and other andesitic volcanoes mentioned in the text. Thick dashed line in inset map represents the southern limit of inferred en-echelon cross-fracture structures (Wright, 1992).
www.godlikeproductions.com/external? [link to petrology.oxfordjournals.org]

Thread: CREEPY EVENT OVER SWEDEN!!!

The Strange Spine of New Zealand’s White Island

[link to www.wired.com]

A couple New Zealand volcanoes got updates from GNS Sciences on Wednesday, but the oddest of the pair was the news from White Island. The volcano had a small eruption in August during the “Big Kiwi Volcano Week” when White Island and Tongariro erupted and the pumice raft was discovered in the Kermadec Islands. That small event was the first explosive eruption at White Island since 2001 and since then, GNS Science geologists have been watching the island to see if it might be headed into a new period of unrest. This is especially important considering that tourists are still being taken to the island on a regular basis. However, that may change now that “hell hog” (as my wife called it; see above) was spotted in the crater.

[b]It is a little disconcerting that tour operators said they noticed the dome two weeks ago and only now was GNS Science made aware of this new event. Even a small dome like this might suggest that new lava might be forcing its way up the conduit, getting rid of this cooler remnant lava that was in the way. Or worse, the plug could allow pressure to build behind it, leading to an explosive eruption (phreatic or magmatic).

GNS Science also updated us on the activity at Ruapehu, where there is still concern that an eruption is likely in the works. Higher than normal temperatures have been observed under the Crater Lake at the summit of the volcano and Gill Jolly of GNS Science says that the conduit beneath the crater lake might be sealed at a depth of a few hundred meters below the lake. Any time a conduit might be partially or fully sealed, the threat of an explosive eruption increased because pressure from gases coming off the magma can build rapidly. Even so, the alert status at Ruapehu remains at Level 1/Yellow as GNS Science says that although the likelihood of an eruption might be high, it is not inevitable.

Blazar 12/21/12

hiya AC

what is blazar?

hiya luis

what do you think this was over sweden??

Hi my friend, in my thread people think it was a meteorite... i think it's possible too...

oh, ok, it sounds like it must have been a big one

and what do you think about the rapidly growing spiny dome at white island?

i wonder how often do they appear/grow so quickly like this?

well it's very strange and dangerous... even the vulcanologists are confused...

yes, i see that eric is worried about it

do you have any links for comments from other vulcanologists about it?

Volcanic hazards at White Island

VOLCANIC HAZARDS AT WHITE ISLAND
by J.W. Cole+ , I.A. Nairn* & B.F. Houghton*

INTRODUCTION

White Island is currently New Zealand’s most frequently active volcano. Situated 48 km offshore in the Bay of Plenty (Figure 1), its activity is often clearly visible to inhabitants of the surrounding region. The island was the scene of one of the three major volcanic disasters in New Zealand when 11 sulphur miners were killed there in 1914 (the other disasters were the 1886 Tarawera eruption, and the 1953 Tangiwai rail disaster). Since 1976, White Island has been more active than at any other time in the last few hundred years, and has aroused considerable public interest in the level of volcanic hazard it presents to people in the Bay of Plenty region.

Frequent explosive eruptions present an obvious threat to the increasing number of visitors to White Island, and to boats in close proximity offshore. The threat diminishes rapidly with distance, and no eruptions during the 160 years of White Island’s written history have been large enough to produce significant effects on the Bay of Plenty coast. However, recent scientific investigations have shown that White Island has a potential to produce large eruptions, although these are apparently unprecedented in the long life of the volcano.

The volcanic hazard arising from White Island has therefore to be assessed under two headings: (a) the obvious but local risk arising from typical White Island eruptions affecting the relatively few people on or close to the island at any one time, and (b), the possible but much less likely, chance of an eruption big enough to affect the large number of people and investments around the Bay of Plenty coast.

This booklet is intended to make information on the volcanic history and hazards at White Island available to residents of the Bay of Plenty region.

WHITE ISLAND ERUPTION HISTORY

White Island (Figure 1) is the summit of a large (16 by 18 km) submarine volcano which has grown up from the sea floor at 300m to 400m depths. Only half the height and a very small proportion of the volume of this volcano are above sea level. The main crater (Figure 1) was formed in prehistoric times, apparently by the collapse of three overlapping roughly circular subcraters (Figure 2). The eastern subcrater was formed first, and now contains only minor hot spring activity. The central subcrater contains the Donald Mount fumaroles (vents emitting steam and hot gases), and the Noisy Nellie and Donald Duck craters and fumaroles. The western subcrater contains most of the eruption sites that have formed since 1960 and has been the main focus of activity during the island’s recorded history. Deep pits mark the sites of recently active vents. Most of the present main crater floor lies less than 30m above sea level, and has an irregular surface covered by mounts of avalanche debris from the 1914 disaster.

Figure 1 (See above) Map of White Island showing positions of features on the island in 1990. The main crater is the near-flat area which extends between 1978/1990 Crater and the coast at Shark, Wilson and Crater bays.



Activity at White Island as far back as 16,000 years ago is recorded by volcanic ash layers found in ocean floor sediment drill cores, but the island was undoubtedly active long before this time. The ocean floor core data provide the only presently available record of the prehistoric activity of White Island, as no old ash deposits from the volcano have yet been identified on the North Island. In fact, there is no evidence that White Island has ever significantly damaged the North Island, at least during the last 50,000 years of good geological record.

The written history of White Island observations begins in 1826; since then a state of continuous low level activity with intermittent small eruptions has been recorded. The crater floor was often flooded by hot lakes, until these were permanently drained in 1913 so that sulphur deposits on the crater floor could be mined. In September 1914 the southwest corner of the high crater wall (see Figure 2) collapsed to produce a hot avalanche which buried 11 sulphur miners and destroyed buildings and equipment at the eastern end of the crater. Mounds left by this avalanche are visible in Figure 3.

Since 1914 new vents have formed in the west and central subcraters, associated with small steam and ash eruptions. "1933 Crater" (Figure 2A) formed in that year during an explosive ash eruption; "Noisy Nellie Crater" formed prior to January 1947; "Big John Crater" grew to 50 m diameter during eruptions between 1962 and 1965. A steam and ash eruption in November 1966 accompanied formation of the 60m diameter, 120m deep new vent "Gilliver Crater". Rudolf vent grew from a fumarole during ash eruptions in 1968, to reach 45m diameter and 120m depth by 1969. Some ash fell on the North Island during these eruptions. Two years later, a single explosive eruption formed "1971 Crater".

[link to www.wi.co.nz]

John Seach @johnseach
4 volcanoes on raised alert level in #Vanuatu. Ambae, Ambrym, Gaua, Yasur.

Threads in all caps = disregard.

WHITE ISLAND New Zealand 37.52°S, 177.18°E; summit elev. 321 m

On 12 December the GeoNet Data Centre posted a report describing a new lava dome at White Island that volcanologists recently noticed. The spiny lava dome was 20-30 m in diameter and grew in a crater formed during an eruption on 5 August. A prominent steam plume rose from the dome. Comments from tour operators at White Island suggested that the dome may have been visible two weeks earlier, but not as clearly as on 10 December. The Alert Level was raised to 2 (on a scale of 0-5), and the Aviation Colour Code was raised to Orange (second highest on a four-color scale).

Geologic Summary. The uninhabited 2 x 2.4 km White Island, one of New Zealand's most active volcanoes, is the emergent summit of a 16 x 18 km submarine volcano in the Bay of Plenty about 50 km offshore of North Island. The 321-m-high island consists of two overlapping stratovolcanoes; the summit crater appears to be breached to the SE because the shoreline corresponds to the level of several notches in the SE crater wall. Throughout the short historical period beginning in 1826 the volcano has had long periods of continuous hydrothermal activity and steam release, punctuated by small-to-medium eruptions. Its activity also forms a prominent part of Maori legends. The most recent eruptive episode, which began on 7 March 2000, included the largest eruption at White Island in the past 20 years on 27 July.

[link to www.volcano.si.edu]

New Zealand Earthquake Report
Magnitude 5.2, Thursday, December 13 2012 at 1:53:23 pm (NZDT) reviewed
Felt it?
Quake Details
Information about this earthquake and historical location data.

Public ID 2012p937941
Universal Time December 13 2012 at 0:53:23
NZ Daylight Time Thursday, December 13 2012 at 1:53:23 pm
Latitude, Longitude -31.07, -177.12
Intensity ? strong
Focal Depth 33 km
Magnitude 5.2
Location 940 km north-east of Whakatane
Agency WEL(GNS_Primary)
Type earthquake
Status ? reviewed
Quality ? best

[link to www.geonet.org.nz]

Hi Sis!
Just wanted to send you some xxx and I'm thinking about you as I'm watching my area.

CYOB #2 Cyclone Evan #1 13th dec 2012 mov

Published on Dec 12, 2012
CYOB #2 . There is now a Category 2 Cyclone in the area we were observing on the 9th.

hiya sis xxxx

wow you are getting lots of quakes

quakes seem to be building here too..

i am very unhappy to see that the rarotonga graphs have been taken off line!!!

because SOMETHING is building volcanically there

[link to www.geonet.org.nz]

this is not good

and still very messy lumpy signals on the northland drum

[link to www.geonet.org.nz]

3.6 18:26:57 Thu 13 Dec 2012 Depth: 26.9 km

Yes we are and we have been hearing the rumbling for quite a few days now along with others who are calling me. The quake we felt today wasn't that big but we heard rumbling and it vibrated which was strange. I have had this feeling I just can't shake for 3-4 days. I've tried to keep busy with work, pray, meditate. Can't put my finger on it just a sense of apprehension like I had before we had that last quake. Could just be the times. I hope you stay safe. I'm sending you mail. xxx

dear sis, please stay safe, we all love you heaps xxx