{There was a great earthquake} (seismos megas egeneto).
"There came a great earthquake." Jesus spoke of earthquakes in
his great eschatological discourse ( Mr 13:8 ). In  Mt 24:29  the
powers of the heavens will be shaken. Seismos is from sei(935c),
to shake, and occurs also in  Re 8:5  11:13,19  16:18 . The
reference is not a local earthquake like those so common in Asia
Minor. {As sackcloth of hair} (h(9373) sakkos trichinos). Sakkos
(Attic sakos), Latin _saccus_, English _sack_, originally a bag
for holding things ( Ge 42:25,35 ), then coarse garment of hair
(	richinos, old word from 	hrix, here only in N.T.) clinging
to one like a sack, of mourners, suppliants, prophets leading
austere lives ( Mt 3:4  11:21  Lu 10:13 ). Here the hair is that
of the black goat ( Isa 50:3 ). Cf.  Joe 2:10  Eze 32:7f.  Isa
13:10  Mr 13:24f . See  Ec 12:2  for eclipses treated as symbols
of old age. Apocalyptic pictures all have celestial phenomena
following earthquakes. {As blood} (h(9373) haima). In  Ac 2:20  we
find Peter interpreting the apocalyptic eschatological language
of  Joe 2:31  about the sun being turned into darkness and the
moon into blood as pointing to the events of the day of Pentecost
as also "the great day of the Lord." Peter's interpretation of
Joel should make us cautious about too literal an exegesis of
these grand symbols.