Can a major asteroid impact trigger volcanic eruptions around the world?

Question

Think of it this way, if the Earth is compared to an egg with many cracks in it representing the magma moving to the surface, then if pressure is suddenly applied to the hard crust this should force more yolk(magma) out, right?

Answer 1

Andamook is quite right.

The impact of a large asteroid not only can trigger volcanic activity but has actually done so in the past. The Ventersdorp Dome in South Africa has now been accepted by geologists as an impact crator. A very large one in fact. That asteroid penetrated so deep that molten lava flowed to the surface of the earth and covered a huge area to a considerable depth.

Geology can be fascinating!

Answer 2

in a word, yes.

Answer 3

Yeah, the deccan traps in India (I think) are supposed to be caused by an asteroid impact on the opposite side of the earth. The gases given off contributed to the K-T boundary that is the extinction of the dinosaurs

Answer 4

I'm not sure about the "around the world" part, but impacts DO cause melting and sometimes are linked to massive volcanic eruptions. One answer already mentioned the Deccan Traps, and here is a link to a brief article regarding that and its possible link to the Shiva crater:

http://www.depts.ttu.edu/vprgs/dinosaurs...

Note that the above article doesn't suggest that the impact *caused* the Deccan Traps (the age dates don't seem to match up well enough), but the impact may have enhanced the eruptive activity.

While the Shiva impact doesn't seem to be the direct cause of the Deccan Traps, some have suggested that the Chicxulub impact which did occur around the period that the Deccan eruptions started may have have been even though it was almost half a world away. This "impact-induced antipodal volcanism" is a process that has been suggested by evidence on Mars.

The impact that caused the Shiva impact crater may have also created a "crack" that became a spreading ridge between India and the Seychelles. This in turn would have altered the plate tectonic dynamics of the plate boundaries between India and Africa and Africa and Antarctica.

No matter what the size of the impact melting can occur as the kinetic energy of the impacting body is converted to heat can can cause melting. Also, the blowing out of material from a crater can cause decompression melting underneath the impact site. Obviously smaller impacts will produce less melting and affect a smaller area.

I do want to point out that the idea of a thin solid shell over a liquid interior isn't totally accurate. The layer right under the crust is more like a plastic, and then the mantle is more like a solid (it can't melt due to the high pressure). So, while we are familiar with images of lava running over the surface, like in Hawaii, it really isn't like that under the crust so it's not really as simple as cracking the crust and having more magma ooze out.

Another difficulty with this question as the farther back you go, the larger the error range in dating events. So, if we have impact event dated to 65 Ma +/- 0.9 Ma and a volcanic event dated to 64 Ma +/- 0.1 Ma there is the possibility that both occurred around 64.1 Ma or that they are separated by 2 million years! So it can be difficult to definitely link two such events.  

Answer 5

You get a "YES" Vote from me also.