Could Queensland's extinct volcanoes come back to life?

[grubstake]

https://www.abc.net.au/news/2023-02...ds-queensland-when-could-they-erupt/101952536

 

[user 4386]

Simple answer - almost certainly.

The last Victorian/South Australian eruptions were about 3500-6000 years ago and Queensland was not a lot older (Kinrara would have been 7000 years). The indigenous inhabitants of both areas record eruptions in their history (stories) and their implements have been found buried under volcanic tuff.

Seismic works indicates that molten magma is still in a chamber near Flinders Island in Bass Strait - I am not familiar with North Queensland seismic data.

 

[David-Karratha]

I’m not a geo, but I seem to recall that until it erupted, Mt Pinatubo was considered “extinct”. https://pubs.usgs.gov/fs/1997/fs113-97/

 

[user 4386]

I’m not a geo, but I seem to recall that until it erupted, Mt Pinatubo was considered “extinct”. https://pubs.usgs.gov/fs/1997/fs113-97/

Just dormant. It had last erupted in the 1500s and before that a few years BC. Periods of quiet like that are common with volcanoes. Even tens of thousands of years of quiet are not uncommon.

 

[Hawkear]

I seem to remember hearing or reading somewhere that there are natural hot springs in Victoria that are associated with remnant volcanic heat. Around the Daylesford and Warrnambool areas.
Hard to specify which as a number that are now advertised as hot springs are artificially heated.
I know that deep artesian wells produce water at high temperatures and have wondered if there is any essential difference between these and springs associated directly with volcanic heat.

 

[user 4386]

I seem to remember hearing or reading somewhere that there are natural hot springs in Victoria that are associated with remnant volcanic heat. Around the Daylesford and Warrnambool areas.
Hard to specify which as a number that are now advertised as hot springs are artificially heated.
I know that deep artesian wells produce water at high temperatures and have wondered if there is any essential difference between these and springs associated directly with volcanic heat.

Firstly, the springs at Daylesford are not hot. Just aerated (full of carbon dioxide)

When springs ARE hot, they can be one of two types. It can be because they are heated by volcanic heat (e.g. North Island NZ). These are often very high temperature and the steam can be used to drive turbines to produce electricity.

Alternatively, the second type is because they are not volcanic but have come up from great depth (all Australian hot springs on the mainland eg along the Oodnadatta Track, Mornington Peninsula, Portland). The deeper in the Earth you go, the hotter it is (around 35 degrees C per km depth on average). However these tend to not be as hot (usually well below boiling). We use some of these, such as thermal baths on the Mornington Peninsula and (I think) to heat a swimming pool in Portland. We have tended to neglect this sort of heat (eg buildings in Paris circulate the water through pipes to warm buildings). There are a few areas where the heat gradient is higher (so temperatures near boiuling occur at less than 2 km depth, as in SW Queensland, because of rocks with elements undergoing radioactive decay - we are experimenting with pumping cold water down into these rocks to heat it enough to run turbines for electricity. Our main areas like this are SW Queensland and northeastern South Australia (unfortunately far from most population centres).

Both types can either discharge naturally at surface, or we can drill down to reach them. There can be minor difficulties, in thar water from both tiypes tends to precipitate minerals in the pipes/boreholes they flow through, so that borehole casing etc has to be pulled every 4 years or so to clean out the minerals that are clogging them.

 

[grubstake]

Alternatively, the second type is because they are not volcanic but have come up from great depth (all Australian hot springs on the mainland eg along the Oodnadatta Track, Mornington Peninsula, Portland). The deeper in the Earth you go, the hotter it is (around 35 degrees C per km depth on average). However these tend to not be as hot (usually well below boiling). We use some of these, such as thermal baths on the Mornington Peninsula and (I think) to heat a swimming pool in Portland.

Also in this category are the well-known Lightning Ridge thermal baths:
https://www.visitnsw.com/destinatio...-ridge/attractions/lightning-ridge-bore-baths