The earth itself is inanimate. This speaks of Gods help manifested through nature , a common aspect of Gods miraculous dealings with his people (Ex. Ex. 9:23-25; Jos. Jos. 10:11; Job Job 38:22-23; Isa. Isa. 11:15; Eze. Eze. 38:22). Perhaps the most dramatic example of the past is the parting of the Red Sea by an unnatural natural phenomenon: the east wind (Ex. Ex. 14:21).
the earth opened its mouth and swallowed up the flood
Swallowed is κατέπιεν [katepien] , a compound word meaning drink down.1 Previously, God used the earth to literally swallow Korah and his household. So they and all those with them went down alive into the pit; the earth closed over them, and they perished from among the assembly (Num. Num. 16:33 cf. Num. Num. 26:10; Ex. Ex. 15:12). It seems likely that something similar will occur to those who pursue the woman.
1 Frederick William Danker and Walter Bauer, A Greek-English Lexicon of the New Testament and Other Early Christian Literature (Chicago, IL: University of Chicago Press, 2000), 416.