Replace the first paragraph of “Topology” with:

All Islands have a topology, which is a list of levels. A level is an integer number, and may be referred to by its position in the list. The default value for Topology is a single level with 5 land. An island’s Land is the sum of the Levels in its topology. The first level of an island’s topology is its top, and the last level is its bottom. If an island’s land is increased without specifying which level is increased, the bottom level of its topology is increased.

The following sentence is flavour text: so, for example, an Island with a level of 3 might have a Land score of 5,0,7, indicating that the top level has 5 units of exposed land, the second has zero (i.e. sheer cliffs), and the third level has 7 units of exposed land surrounding the cliff faces leading up to level 2.

in tectonics, change all instances of “layer” to “level” and “layers” to “levels”

change:
Add a new level with 0 land to the beginning of their topology
to:

Add a new level with 0 land to the bottom (end) of their topology

change:
increase its first X levels by 1
to:

increase its bottom (last) X levels by 1

change:
add a level to its beginning
to:

add a level to its bottom (end)

change:
add a level to its end with pressure land
to:

add a level to its top (beginning) with pressure land

change:
of the island’s lowest level
to:

of the island’s bottom level