A massive undersea <a href="https://en.wikipedia.org/wiki/1833_Sumatra_earthquake" id="mwlA" rel="mw:WikiLink" title="1833 Sumatra earthquake">earthquake</a>, estimated magnitude between 8.7 and 9.2, rocks <a href="https://en.wikipedia.org/wiki/Sumatra" id="mwlQ" rel="mw:WikiLink" title="Sumatra">Sumatra</a>, producing a massive <a href="https://en.wikipedia.org/wiki/Tsunami" id="mwlg" rel="mw:WikiLink" title="Tsunami">tsunami</a> all along the Indonesian coast.