but theese stock photo agencies - they're just thieves.
As there are Alamy, Shutterstock, Dreamtime and others.
They browse the internet for unclaimed pics which might be of interest, brand their watermark on it and put them into their stock.
But I would't pay them.
Since they took that pic from some unprotected foreign sorce anyway You can try a 'reverse pic' search on google to find the same pic w/o watermark - which You then can use freely. I succeeded on this several times.
this is what I came up with:
https://pixfeeds.com/images/natural-disasters/tsunami/1280-508631194-tsunami-tidal-wave-flash-flood.jpg
https://s1.kikar.co.il/th/data/auto/nadm/ns/au9c7uxj__w643h425q95.jpg
they both look as if they have no watermark - so You might use them.
watermark --> copyright claim.
either imgflip won't feature it or the owner can sue You if you use it w/o a licence.
(and they have bots to search the internet)
but we can fix that.