Eorþ-dyne

According to the Old English Dictionary:

es;

eorþ-dyne

m. Earth din, an earthquake; terræ mōtus :-- On ðisan gére wæs micel eorþdyne in this year [A. D. 1060] was a great earthquake, Chr. 1060; Erl. 193, 31; 1122; Erl. 249, 14. eorþ-dyne