Is the mantle a liquid or a solid?

lol. hes a great bloke. and surprisingly xenophobic for a dutchman living in england

he is a brilliant man, though he gave us all jip for student flu, and today he doesnt come in because he has the flu.

I remember when he was talking to us about polar wandering, he said something along the lines of "the poles wander quite a lot, and come over here and steal jobs".

His german jokes are always good too.

What does that have to do with anything?

shes talking about the mantle, you are talking about the outer core - that is liquid.

The mantle is a ductile solid, sometimes described as a liquid mush of crystals.

So a ductile solid is the definition

The upper mantle as part of the lithosphere is solid and virtually non ductile, hense lithosphere including the upper mantle (lithos meaning rock)

the lower mantle becomes more ductile due to mineral assemblages changing, and p/t changes but is definitely not liquid. as stated before s waves would not pass through it if it were


and whoever said plate motion is driven by convection currents, and heat production is due to radioactive elements should be shot

Why should they be 'shot'? That's actually a perfectly reasonable thing to say because most heat production from the earth IS due to radioactive decay! And despite not knowing what the main driving force behind plate motion is, convection currents are said to be a possibility...

Gravitational energy of accretion Joules
Present density structure 24900 x 10p/o28
Uniform Earth 23300 x 10p/o28
Core separation 1610 x 10p/o28
Inner core formation 8.3 x 10p/o28
Separation of crust 7.6 x 10p/o28
Radiogenic heat 800 x 10p/o28
Residual (stored) heat 1800 x 10p/o28
Tidal dissipation 200 to 300 x 10p/o28
Present rotational energy 21 x 10p/o28

p/o = to the power of (dunno how to get superscript up atm

so radioactive decay produces 1.54% of the current heat output of the earths interior, and most heat is maintained by original accretion and current gravitational effects

and no scientist who has much credibility will defend convection currents now, for a couple of basic reasons
1 if you draw a map of what convection flows would have to be like in order to make current plate motion it just doesnt work. if it did work the south american plate would split in two and thered be a subduction zone down the coast of brazil
2 in order for convection currents to work the mantle must be liquid enough for the flow of heat, but viscous enough to cause friction on the plates and make them move. it isnt.

I will admit that I was wrong in thinking radioactive decay dominates heat output, but you are still being very unfair in saying that is completely and utterly ridiculous for anyone to think that radioactive decay is a major source of earth's heat. Geologists at both A-level and early undergraduate level are taught that radioactivity is one of the dominant sources of heat in the Earth, and I highly doubt my lecturers would have emphasised its importance if they really didn't think it wasn't important.

Second, most theories for driving forces behind plate motion are understood extremely poorly. ANY textbook will cover the possible theories for driving forces behind plate motion, and each and every textbook you read - including newly updated ones - will mention the possibility of convection currents playing a role, and I think it's personally reasonable for someone to mention them.

I'm not saying you're necessarily wrong or anything btw I'm just trying to tell you that it's a little unfair to tell people they 'should be shot' for mentioning any of the above two when they are commonly listed in textbooks. You have obviously read more recent research from journals etc, but evidently if the research hasn't translated into textbooks it hasn't been stuff that is widely accepted by the geological community.

so is lava a solid then?

shes talking about the mantle, you are talking about the outer core - that is liquid.

The mantle is a ductile solid, sometimes described as a liquid mush of crystals.

So a ductile solid is the definition

The upper mantle as part of the lithosphere is solid and virtually non ductile, hense lithosphere including the upper mantle (lithos meaning rock)

the lower mantle becomes more ductile due to mineral assemblages changing, and p/t changes but is definitely not liquid. as stated before s waves would not pass through it if it were


and whoever said plate motion is driven by convection currents, and heat production is due to radioactive elements should be shot

There's no need for that. I'm just repeating exactly what i was taught.