Does lava smell?

[nicolab6]

Can anyone resolve a long standing family argument? Does lava smell?

Thanks

Nicky

[The-Mangler]

Read through this-

http://en.wikipedia.org/wiki/Lava


Im pretty sure there would be a sulphur smell somewhere in there!

[NoMercy]

I went to the world's only drive in volcano (at least that's how they described it) in St. Lucia. It stank to high heaven.

[The-Mangler]

Ye I am sure that it is very whiffey

Its with answers like that i understand now why you never post in science or news my shortlegged low iq'd friend........

[KARL]

Lava is a collective name for a wide range natural materials. During an eruption, a lot of various gases escape into the atmosphere, some of them odourless, some of them not, some highly toxic, some not. Once it has set, most lava simply becomes rock/stones, but the more frothy stuff is quite light and friable. Trapped within this latter material are various gases, so if you cause them to escape (e.g. by scraping at it or breaking it) there will often be a smell. The most familiarly occurring smell is that of sulphur, simply because it is the strongest. In itself, lava (i.e. molten or solidified rock) is mostly totally odourless to humans.

[theprof]

I've got first hand experience of this.

I've been a visiting professor at the University of Hawaii at Manoa in Honolulu, Oahu, Hawaii for a good few years now.

I've been to see Mount Kilauea on Kauai Island ("The Big Island") three times since it began erupting in its present cycle since 1983. On each visit, I had a couple of university geologists/vulcanologists with me. This volcano is the largest active volcano in the world.

The noxious stink from the sulpher dioxide contained in the lava flowing towards the sea is unbearable both near the volcano and some distance away as it enters the sea. The experience is both fascinating and frightening at the same time. Entire villages have been decimated in the region by the relentless lava flow.

In my office at the university, I have a 11KG block of the lava that I chipped out of a solidified lava river as a souvenir. The block is completely odourless.

So to answer your question, lava does smell in the liquid state, but not when solid.

[mibn2cweus]

If lava can smell, where's its nose?

[theprof]

It's in the same place as it is in a bottle of wine.

[KARL]

I would take issue with the professor - the materials that come out of the ground in an eruption are not just lava, and once set lava and other mineral masses take many forms. His/her sample appears to be the more solid type with very little or no trapped gas. The rock itself is odourless but gases trapped within it smell, as do the gases that escape as 'belches' (explosions, even) during the eruption. You can release the gases trapped in lava samples by breaking open the "bubbles".

[theprof]

KARL

I do appreciate the points you make regarding the types of emmisions from volcanoes.

However, the questioner specifically referred to lava per se rather than the other materials involved. I would not have insulted nicolab6's intelligence by referring to other materials such as volcanic ash, cinders, tephra, molten rock, hot rock and even mud that can be emitted from volcanoes.

With regard to the lava sample I have in my office, I'm afraid that your reasoning is incorrect.

Let's discuss lava viscosity. Lava can be classified into two broad types as far as viscosity is concerned.

Highly viscous lava does indeed entrap gas that can be released by puncturing the vesicles (your "bubbles") that are contained within the solidified lava. However, this type of lava does not flow readily. Highly viscous lava is the type that is emitted during the traditional concept of a volcanic aruption. But wait a moment; do I hear you say that the traditional concept of a volcanic eruption includes a picture of fast moving lava down the outside of the volcano? Yes, that's right, but and this is a great big but, the very reason that lava flows fast in such circumstances is because the flow rate is proportional to the rate of loss of the trapped gases within the lava. The faster the gases are released, the more rapidly the lava flows.

(continued)

[theprof]

Low viscosity lava behaves quite differently. As you would expect, it flows easily and forms pools and rivers of lava that can flow for many miles without solidifying. However, low viscosity lava does not retain gas vesicles. The gases are released as soon as they are formed. Low viscosity lavas occur in quite a few places in the world notably in broad shield volcanoes. Mount Kilauea that I cited is one such broad shield volcano and the lava it emits is termed "type aa" and/or "pahoehoe".

Sectioning pahoehoe lava to look for vesicles is a futile exercise as it does not contain any. There are no gases present to smell. Consequenly, it follows that whether you sniff the exterior or a cross section of the interior of my 11kg sample, it will remain odourless.

Vulcanologists accept that the least adulterated lava types are low viscosity types. They are therefore, the closest thing to true lava in the sense that nicolab6 was enquiring. This is precisely why I confined myself to discussing low viscosity types in answering the question.

incidentally, I am a "he".

[KARL]

I am not trying to discuss technical niceties nor making any assumptions about anyone's intelligence. I read the question as one coming from not from an academic but a person curious about something she knew little or nothing about (not a matter of intelligence but experience). The term lava may to some mean only a rock product of magma emerging within a limited range of viscosities, but in general all igneous rock emerging from eruptions open to the atmosphere is understood by the public to be lava. There are lots of lightweight lava products which solidify with trapped gas bubbles and are well established under the term of lava - the gases are gradually replaced by air in some cases, in others not. I have been among both examples, some pre-historic, others relatively modern, the geologists whom I have heard discuss these refer to them as lava, and so do I. Some of the eruptions I have seen (not Kilauea) have produced this sort of material, along with sheets of solid rock, presumably something like your lava sample. I have no desire to challenge the sample's inclusion under the name of 'lava' - it is simply one type of it but not the only one. We are agreed that the rock is odourless, any gases present are not always odourless. Of course it is futile to expect to smell gas from a rock that does not contain any. Nicola is free to decide whether her question centres on the rock-gas matrix as a whole (liquid or solid) or whether she is solely interested in the pure rock (perhaps only the limited definition of lava, i.e. with no entrapped gases). She can indicate whether she feels the question has been sufficiently answered.

[nicolab6]

All many thanks for the full detailed answers. For those interested, the reason for the question was a game of Scattergories we played years ago when my husband had to name something that smells beginning with the letter L