Table 2.

Top 15 topics on Reddit after the M7.1 mainshock using GPU-PDMM. Topics on Twitter can be found in⁷

Topic type	Keywords
Description	Earthquake go get quake time make would people know fault big even thing may say year building could think feel
Nuclear	Cause earth base earthquake test evidence say weapon natural ground call fact deep military great mile human bomb science underground
Insurance	Building insurance home cost pay build need state money regulation high city structure price retrofit house code require old new
Discussion	Fault large magnitude scale chance aftershock likely occur would event cause different wave zone high plate move energy predict release
Rescue	Use work call would go stop alert amp get train surgery system patient hospital second need want send take emergency
Big one	Earthquake big quake happen live time year feel one say know hit even day really pretty area come much also
Preparedness	Water need food case put bag make emergency supply power pool buy good work keep kit gas store plan eat
Negative	Get go think people shit see fuck right take make back bad look would want dog way scary hear hope
Hazards	People get damage would go fire tornado bad hurricane take cause city think well see way least probably major kill
Description	Feel shake second move start long yesterday sway first back minute definitely bit aftershock little roll ground rock sit pretty
Description	Earthquake know say really time happen could even also still much live may come quake sure tell actually place lot
Forum	Post comment question thank link use read find report edit bot action ask see concern remove moderator make try message
Unknown	Go would think make good get people thing see way well bad probably look take hope want right try always
Self-rescue	Fall building shake build table run house collapse move stay outside safe wall desk thing bed cover head doorway floor
NBA	Look video see game watch play think make fake would go get movie people right end show room keep stop