Volcanoes!

Alaska's Mount Redoubt volcano has erupted for the first time in 20 years, threatening air traffic and nearby villages with a towering burst of ash. The first blast occurred at 6.38pm Monday NZ time, and it was followed by four smaller eruptions. More eruptions are expected. The 3,108 metre volcano, in a sparsely populated area 170 km southwest of Anchorage, Alaska's largest city with about 260,000 people, had been showing signs of a possible eruption for about two months.

And last week an underwater volcano near Tonga stopped being an underwater volcano, and started building up above the surface, in an eruption that sent clouds of smoke, steam and ash thousands of metres into the sky, forcing air traffic to divert around it. Some great pictures can be found here. The Tongan earthquake on Friday morning which sparked a tsunami warning was not directly related to the eruption.

Tsunami? Not today thankfully

So I was enjoying a bit of a sleep-in on Friday before heading out to the final day of the Joint Centre for Disaster Research's Emeregency management Summer Institute when my phone wakes me up to tell me that there's a National Advisory - Tsunami: Potential threat to NZ.

I woke up in a hurry, let me tell you!

An earthquake measuring 7.7 on the Richter Scale had occurred at 7.18am NZDST, at a depth of 48km, in the region of the Tongan islands. 23.0 South, 174.8 West.

An earthquake of this size automatically generates a tsunami warning from the Pacifc Tsunami Warning Centre, because such earthquakes often generate destructive tsunamis that can strike coastlines near the epicenter within minutes or hours, so any warning is better than none. The centre then monitors sea level gauges nearest the region and reports if any tsunami activity was observed.

GNS Science convened the tsunami expert panel and all the available NZ and international data about the earthquake and sea levels was being closely monitored and analysed.

The only tsunami wave activity reported was from Niue at 8.11am NZDST, where they had waves 4cm higher than usual every 6 minutes, so the warning was cancelled and we could all relax and get on with our day.

Certainly caused a bit of a flurry of activity - there is nothing more frustrating than waiting for your computer to start up in the morning when there is something time-critical that you need to look at.

Disaster breeds disaster

As if dealing with the effects of a cyclone wasn't hard enough on its own, Queensland now has to deal with a cocktail of 650 tonnes of fuel and fertiliser dumped into the ocean off its south-east coast after 31 shipping containers fell overboard during the storm and damaged the fuels stores in the hull of the Pacific Adventurer. Aerial reports estimate the oil slick covers three nautical miles by 500 metres and is drifting north-west. The fertiliser should dilute well enough that the only thing it'll do is cause an algal bloom, but the oil slick has the potential to kill any wildlife that it comes in to contact with. The shipping containers are still bobbing around out there somewhere.

http://www.stuff.co.nz/world/australia/2252982/Oil-spill-threatens-wildlife

Keep missing them...

Another earthquake that I missed... *sigh*

This one happened at 10.46 last night, and was centred about 50km south-east of Blenheim. Measured 4.3. Apparently it was felt in Wellington, but obviously not by me.

http://www.geonet.org.nz/earthquake/quakes/3057877g.html

There was also a quake measuring 4.7 up near Taupo at 4.49 yesterday afternoon.

http://www.geonet.org.nz/earthquake/quakes/3057749g.html

Cyclone Hamish

While Victoria begins to bury its dead from the February fires, Queensland is bracing itself for Cyclone Hamish. It was rated at Category 5 early this morning (same size as Cyclone Larry which wreaked havoc), but appears to be weakening to a low Category 4, and evacuation plans in some areas have been dropped.

http://www.stuff.co.nz/world/australia/2161407/Evacuation-cancelled-as-Hamish-weakens

Our own bad weather last week had yachties up north battening down the hatches, and still getting battered about, and it looks like we're in for a cold snap over the next few days. And just this morning I'd been thinking how nice the weather's been here lately - just enough rain to keep the grass growing, and stop most of the countryside from catching fire (except for Owhiro Bay, but that one was a bit suspicious...), but still lots of nice sunny days. Oh well. Time to dig out the woolly jumper...

Crikey! That was close!

Early on Tuesday morning an asteroid between 30-50m in size zoomed past the Earth, just 60,000km above the southwestern Pacific. I know that sounds like a long way away, but the moon is seven times that distance from here. No one has ever seen something that big come so close before. If it had hit New Zealand, it would be like having a nuclear bomb go off, and it would have devastated a large area. If it had hit the sea, it would have generated a tsunami. Astronomers first spotted it on Friday, and probably promptly crapped themselves until they realised that it's trajectory meant it wasn't going to hit us.

http://www.stuff.co.nz/science/2001262/Asteroid-bolts-past