First Contact
It didn't take too long to figure this out, but i believe it's really accurate.
I know there's another tab for some AVA riff somewhere on the net but I didn't take the 
to read it.

Intro
e---9--------9--------9--------9--------9--------9--------9--------9------------|
B-------10-------10-------10-------10-------10-------10-------10-------10-------|
G-----6----6---6----6---7----7---7----7---9----9---9----9---7----7---7----7-----|
D-------------------------------------------------------------------------------|
A-------------------------------------------------------------------------------|
E-------------------------------------------------------------------------------|

There is also another way to do the intro which I find easier and sounds a bit more accurate.
e-----------------------------------------------------------------------------------------------------|
B---14----------14----------14----------14----------14----------14----------14----------14------------|
G---------14----------14----------14----------14----------14----------14----------14----------14------|
D------11----11----11----11----12----12----12----12----14----14----14----14----12----12----12----12---|
A-----------------------------------------------------------------------------------------------------|
E-----------------------------------------------------------------------------------------------------|

The second part to the riff can start out like this:
e---------------               e-----------------|
B-----10---10---               B-----------------|
G---6----6------ or like this: G------14----14---|
D---------------               D---11----11------|
A---------------               A-----------------|
E---------------               E-----------------|

Of course, I prefer the second way.

The rest of the second part to the riff.
e-----------------------------------------------|
B-----------------------------------------------|
G------14----14----10----10----9----9---9---9---|
D---11----11----12----12----11---11---9---9-----|
A-----------------------------------------------|
E-----------------------------------------------|

Also, they hit an A octave as Tom usually tends to use in his songs.
e---------        e---------------------|
B---------        B---------------------|
G--------- and... G---------------------|
D---7-7---        D---7---7---7-7-7-7---|
A---0-0---        A---0---0---0-0-0-0---|
E---5-5---        E---5---5---5-5-5-5---|

I cannot wait for this album.