Here's a table which shows the amount of damage caused by a gas pocket at a given depth and radiator. (Rounded to nearest integer)

Depth Stock Lv1 Lv2 Lv3 Lv4 Lv5

5000 -133 -106 -100 -80 -53 -26

5100 -140 -112 -105 -84 -56 -28

5200 -146 -117 -110 -87 -58 -29

5300 -153 -122 -115 -92 -61 -30

5400 -160 -128 -120 -96 -64 -32

5500 -166 -133 -125 -99 -66 -33

5600 -173 -138 -130 -104 -69 -34

5700 -180 -144 -135 -108 -72 -36

5800 -186 -149 -140 -111 -74 -37

5900 -193 -154 -145 -116 -77 -38

6000 -200 -160 -150 -120 -80 -40

6100 -206 -165 -155 -123 -82 -41

6200 -213 -170 -160 -128 -85 -42

6300 -220 -176 -165 -132 -88 -44

6400 -226 -181 -170 -136 -90 -45

6500 -233 -186 -175 -140 -93 -46

6600 -240 -192 -180 -144 -96 -48

6700 -246 -197 -185 -148 -98 -49

6800 -253 -202 -190 -152 -101 -50

6900 -260 -208 -195 -156 -104 -52

7000 -266 -213 -200 -160 -106 -53

7100 -273 -218 -205 -163 -109 -54

7200 -280 -224 -210 -168 -112 -56

7300 -286 -229 -215 -172 -114 -57

So, I've been reading and looking into the function that generates the terrain in the game. First, certainly seed-able, but it would need some adjustments to how it picks when to generate terrain. The hard thing about the function is figuring out what number correlates to what tile. It's hard to tell what is actually being generated without being able to edit the code and run the game. Interesting knowledge, I'm sure someone has counted it at some point but earth generates down to -7500 feet. Always wondered what that depth actually was. Also, the wall between the earth and Satan is at 7300 feet. I'm pretty sure we already knew that too though, so nothing too useful.

All in all, its hard for me to figure out what the spawn rates for various materials are, when I can't tell what value is what material. Also, frankly, the function is kinda messy so it's hard to read as is.

I don't know if anyone has figured this out yet, but I figured it'd be useful info to know. I got a look at some of the games source code, and the function that triggers earthquakes is a 1 in 20 chance every time you leave a shop, so keep that in mind.