For all things relating to tectonic plate collisions. Earthquakes, volcanic eruptions and tsunamis... the Pacific ring of fire and world-wide. Please create new threads for stronger earthquakes when they happen above magnitude 5.0.
jamie.haultain wrote:Interesting..... I hadnt picked up on that.
Sometimes their location description is not very useful unfortunately. The Ruapehu quakes are described as "20km north-east of Ohakune". There were another 2 tiny quakes early this morning, magnitudes 0.7 and 0.9.
I dislike their new site & find the info I used to look at regularly difficult to view on it, so seldom look now. Thanks for the heads up re this, hopefully they won't be embarrassed over an eruption of sorts like Tongariro did again.
Latest quake map for Ruapehu. A magnitude 2.7 right on the mountain at 12.48pm today, easily the biggest yet.
Ruapehu_Quakes_081112.jpg
The locations and magnitudes for older quakes are still changing (Geonet are reviewing them multiple times - they are really taking an interest in them!)
You do not have the required permissions to view the files attached to this post.
Pressure is building up in the Crater Lake on Mt Ruapehu, increasing the likelihood of an eruption in the coming weeks, scientists say.
GNS Science said recent measurements taken on the volcano over the last few weeks indicated that eruptions were more likely "over the next weeks to months".
The Aviation Colour Code has increased from green to yellow as a warning for those flying over the region, but the Volcanic Alert Level remained at level 1.
Pressure was believed to be building up under the Crater Lake, and a sudden release of that pressure may lead to an eruption.
"We are monitoring Ruapehu closely, but it often does not give any immediate warning that it is going to erupt," GNS Science Duty Volcanologist Steven Sherburn said.
GNS Science believed the temperature a few hundred metres beneath the crater was about 800 degrees Celsius but the lake itself was only 20degC.
"This suggests the vent is partly blocked which may be leading to a pressure build-up beneath Crater Lake.''
Small earthquakes have been occurring about 5 kilometres beneath the summit of Ruapehu since late October, GNS said
Since late-October small earthquakes have been occurring about 5 km beneath the summit area of Ruapehu, but these may not be directly related to the high temperatures beneath Crater Lake as the earthquakes are much deeper.
16 November 2012, 10:00 am - Increased likelihood of eruptions at Ruapehu; Volcanic Alert is at Level 1; Aviation Colour Code is raised to Yellow
Recent measurements at Ruapehu indicate that the likelihood of eruptions has increased, GNS Science said today.
The Aviation Colour Code has increased from Green to Yellow, but the Volcanic Alert Level remains at 1.
GNS Science Duty Volcanologist Steven Sherburn said, “We have been measuring changes at Ruapehu over the last few weeks and believe these changes make eruptions more likely over the next weeks to months”.
“We are monitoring Ruapehu closely, but it often does not give any immediate warning that it is going to erupt,” Dr Sherburn said.
"We think that the temperature a few hundred metres beneath Crater Lake is about 800 °C, but the lake itself is only about 20 °C. This suggests the vent is partly blocked which may be leading to a pressure build-up beneath Crater Lake. A sudden release of the pressure may lead to an eruption."
Since late-October small earthquakes have been occurring about 5 km beneath the summit area of Ruapehu, but these may not be directly related to the high temperatures beneath Crater Lake as the earthquakes are much deeper.
Yes, all very well, but it is a trend worth following and something out of the norm. A 10C increase is nothing to scoff at, and indicates rising magma.
Vertigo wrote:Yes, all very well, but it is a trend worth following and something out of the norm. A 10C increase is nothing to scoff at, and indicates rising magma.
From what I heard, the rise in temperature is likely due to the clearing of a blockage beneath the crater (which was preventing heat flow into the crater lake)
Well, I haven't studied it at an academic level, just out of my own interest
From what I understand, volcanic quakes are similar to regular earthquakes, caused by rock fracturing. They are really just small shallow quakes under a volcano, which may or may not be caused by magma intrusion. These are what we saw before the Tongariro eruption. (note: I am not speculating an eruption is coming, just that eruptions are often preceded by such activity).
Volcanic tremor according to Geonet: "This is a continuous or semi-continuous ground vibration produced by degassing, underground boiling, magma movement, ash eruptions and a range of other sources. Scientists often do not know the precise cause of the volcanic tremor."
Last edited by David on Sat 30/04/2016 21:03, edited 1 time in total.
jamie wrote:Oh wow interesting. That quake swarm would have been magma rising wouldn't it? So at some point that needs to eject?
Certainly makes you wonder. Two thoughts come to mind. Maybe it's cleared it's throat and the path for the magma is now open and it can rise as necessary and may ultimately lead to an eruption. Or simply they reduced because whatever was going on has subsided. I guess time will tell. At least in recent history the eruptions are not that violent from those 3 volcanos.
