Demiurgos

Throughout human history, hatred of an entire group of people doesn't tend to be rational and well-reasoned.

Throughout human history, hatred of an entire group of people doesn't tend to be rational and well-reasoned.

OK, if I read this correctly, you want a sufficiently intense quake to tear through the ground, even solid rock, leaving a 20m x 150m hole.  Not sure why it has to be exactly 20m x 150m, but OK.  And you want an earthquake on the ground.
 
Note that an explosion loses damage as it moves from center to edges, so an explosion will start damaging, instead of destroying, terrain as it gets further from the center.
 
So Step One seems pretty easy - 10d6 Blast, Physical, Area Of Effect (20m radius, Explosion, Hole in the Center +3/4) (87 Active Points); No Range (-½), Only Affects Targets On The Ground (-¼), Only Does Knockdown, Not Knockback (-0), Linked to Abyss (below; -1/2) 39 real points.  I've left this  one alone.  Note that it loses 1d6 damage for every 2m away from Ground Zero, and 10d6 is not much in a Supers game anyway, but that's OK - it's not there to KO the Supers, at least not directly, right?  Adding dice and radius is easy, if desired.  Note that I replaced Personal Immunity with Hole in the Center.
 
A cubic meter of dirt has PD 0, ED 4, BOD 10.  Roadway has 5 PD, 8 ED, 11 BOD.  A cubic meter of stone is PD 5, ED 10, 19 BOD.  So, should your power tear through dirt, roads, stone?  Let's assume roads, but not solid stone.  These values are from 6e Vol 2 p 171.
 
A 16d6 Physical Blast and it will do 16 BOD as Standard Effect.  That will take out a cubic meter of dirt or roadway.  Now, make it Area Effect and it does this damage to every hex within its area.  But you want it to be 20 meters radius (40 meters diameter) at the top (with a hole in the middle) and 150 meters down.  The closest area for that will be a Cone whose circular area is 20 meters radius, and height 251 meters, so that is more than you wanted.  But if we make it a narrow cone, now it is 20 meters radius and 126 or so meters long.  128 meters narrow cone is a +1 advantage, plus 1/4 to have a hole in the middle.  Its source point is 128 meters below the character, so that's +1/4 Indirect.  Alternatively, it is the same area as a cone, just inverted, so it does not seem unreasonable to forego Indirect and give it No Range - the character does not even have a choice to point it in another direction.
 
So 16d6 Blast, Physical, Standard Effect, AoE 128 m Inverted Narrow Cone w/ hole in the center (+1 1/4), 160 AP, no range (-1/2), No Knockback (-1/4), does not damage living beings (or only earth, stone, etc., or whatever) (-1), Linked to first Blast (-0 or -1/4*) 71 real points
 
* I'd probably allow the extra -1/4 as the powers both have a serious END cost, but I priced it conservatively.  You could also toss Unified Power on both for another -1/4, as weakening one would seem likely to weaken the other.
 
So we end up with 110 points, the explosion damages things on ground level, and the abyss opens.  Mess with the AoE as desired if you want a different shape to the Abyss than a hole sloping inwards from a 20 meter radius, dropping down to 128 meters.
 
As eepjr24 suggests, we could also use Megascale, but that will cost +1 1/2 (+1/4 for AoE, +1 for Megascale, +1/4 for a hole in the center).  We're right about the area where Megascale starts to be less expensive than standard AoE.
 
 

My choice of 100m as the hex size was completely arbitrary. I apologize for not pointing that out. For the +1 Megascale option you can select any set value of greater than 1m and less than or equal to 1km. Play with it till you get what you like.
 
For a 20 meter wide hole that is 150m deep you are going to probably use AOE Line for a 16m by 16m line (using the optional doubling of width or height instead of length and figuring the the approximate area of 20m circle to be the same as the area of a 17.2m square) by 150m. That is a +2 3/4 AOE Advantage, without megascale.
 
With megascale 1m = 20m (+1) you would buy a line that is 8m long (+1/4) pointed straight down only, no range, hole in the middle, etc. At 14d6 no explosion that would net you a hole 20m wide and 160m deep, which is pretty close. As a GM if you wanted to call it 150 I would be fine. Saves you 1 1/2 in advantages and really is a better model IMO.
 
- E