Mount Napier dominates the landscape just south of the Victorian town of Hamilton in western Victoria.

The 440-metre-high volcanic cone slumbers amid the grasslands and manna gum forests of the Western District. It is classified as "dormant" by some, but that would be generous. It is unlikely to wake.

Victoria's dormant and extinct volcanoes probably won't explode back into life, but they serve as a reminder the Western District is an active volcanic region.

And that means new volcanoes in Victoria aren't just likely. They are inevitable.

Ander Guinea-Maysounave, a lecturer in geosciences at Federation University, said it was only a matter of time.

"We are in an active volcanic field. The mechanisms that created those 300-odd eruption points in western Victoria, those are still happening.

"It is much less likely that a volcano that has already erupted will start again. It is a lot more likely a new volcano will form somewhere else. That is almost a given. It is going to happen.

"The follow-up question is when is this going to happen? It may be in 100 years, or 5,000 years. We don't know. We need to have more information to answer that question."

Volcanic eruptions 'practically yesterday'

Mount Napier is comparatively young in geological terms. Its last eruptions occurred about 32,000 years ago. That is practically "yesterday", according to Dr Guinea.

Budj Bim (Mt Eccles) and Tower Hill (Warrnambool) are estimated to have erupted between 33,000 and 40,000 years ago.

Australia's youngest volcanoes are in eastern South Australia, though. Mount Gambier may have erupted 6,000 years ago, while Mount Schank's estimated age is about 5,000 years.

"There are accounts of Aboriginal histories that talk about volcanic eruptions. People have actually witnessed some of those eruptions, which makes sense when we consider the ages given to some of those volcanoes."

Dr Guinea said virtually all of Australia's existing volcanoes would be classed as extinct rather than dormant.

"It's a bit difficult [to distinguish] dormant and active because dormant implies there is potential to be active again," he explained.

"In some places, mountains may be classified as dormant depending on how many years since its last eruption, perhaps maybe 10,000 years, and if it is 100,000 years it may be considered extinct.

"Those numbers may change depending on the source because there is no agreement on that."

Many of Australia's volcanoes exist in a band that begins in Queensland and extends down along the eastern seaboard.

They can be explained by a hotspot deep beneath the Earth's surface.

The hotspot is effectively immobile in reference to the globe but the Australian landmass isn't. As Australia inches slowly north volcanoes have burst forth along a relatively straight line above this hotspot.

"The extinct volcanoes in Queensland are the oldest in that chain, while those in Tasmania are somewhat younger. The steady continental drift means that steadily weakening hotspot is now south of Tasmania," Dr Guinea said.

The problem of the province

The problem with western Victoria and eastern South Australia's volcanoes is they do not occur along this neat band.

"I wish this was an easy thing to explain but it's actually been a heated debate," Dr Guinea said.

"There is general agreement the line of volcanoes on the Australian eastern seaboard are on that hotspot, and a lot of people were trying to explain that western Victorian volcanoes with the same thing.

"There are two problems with the Newer Volcanic Province: first, the volcanoes are a lot younger than those on the eastern side of Melbourne, and secondly they have an east trend from Mt Gambier in the west to just west of Melbourne.

Dr Guinea said no individual mechanism could explain why the Newer Volcanic Province was active. A combination of sub-surface heat and seismic pressure add up to the possible reason.

"We have New Zealand's plate pushing towards us, which increases compression but also creates some deep faults and fractures," he said.

"Because the pushing from New Zealand is not direct but oblique to it, that opens it up to have decompression. 

"By themselves, each of these things doesn't have enough to create enough melting for a volcano but if you combine them together the numbers add up."

That does not guarantee new volcanoes will be in the immediate vicinity of the most recent eruptions on or near the South Australian-Victorian border.

"There was a study published a few years ago that found an anomaly between Daylesford and Bendigo. By itself, it doesn't mean there is a lot of magma and there will be a volcano erupting but that would be one of the signs," Dr Guinea explained.

"There is heat underground, so if I had to bet on where the next eruption would be, then probably, maybe there, but there is not enough research yet."

Landmarks like 'lighthouses'

The Western District's recent and ancient history is intertwined with its volcanic past.

While little would grow in the immediate aftermath of an eruption, the blanket of basalt would ultimately break down into a mineral-rich clay with an abundance of magnesium and iron.

In addition to the rich soils that encouraged plant growth, peaks such as Mount Elephant near Derrinallum served as important landmarks for Aboriginal communities and early European settlers, historian and author Pam McGregor explained.

"There was a small Derrinallum Aboriginal community and Mount Elephant provided shelter but it was also used as a landmark, almost like a lighthouse.

"It was like that in another way for European settlers who were attracted to the incredibly fertile, rich soils."