The earthquake struck at 19:03 local time (12:03 UTC) at a moderate depth of 52.8 km (Indonesian BMKG stated that the earthquake struck at a depth of 10 km). The epicentre was located 147 km off the coast of Sumur, an area which had been previously destroyed by
another tsunami in December 2018. Indonesian geological agency BMKG recorded the magnitude of the earthquake as 7.4 while the USGS recorded it as a magnitude 6.9 earthquake. BMKG subsequently revised the magnitude to 6.9 and its hypocentre to 48 km. The earthquake struck with an
oblique-slip motion. According to experts from the Indonesian BMKG, the earthquake wasn't caused by Sunda megathrust, but rather from a nearby fault, indicated by its north–south motion of the rupture. It was later confirmed that the earthquake was an
intraplate earthquake.
Intensity Moderate shaking were widely reported across Lampung, Banten and West Java. In Jakarta, office workers and apartment residents were evacuated from high rise buildings, citing "strong shaking". The operation of
Jakarta MRT was terminated due to the earthquake. The earthquake could be felt as far away as
Mataram, which was located in
Lombok Island. In
Yogyakarta, residents reported "swaying motion" from the earthquake. The recorded maximum
Mercalli-intensity of the earthquake was VI (strong). The maximum perceived intensity, however, was V (moderate). Residents in coastal areas, especially those in Southern Lampung and Pandeglang Regency, were urged by authorities to evacuate to higher grounds. In Lampung, at least 1,050 people evacuated to the governor's office. Initially, there were unconfirmed reports that water levels had receded in several areas in Banten. These reports were considered as hoaxes as observation of tide gauges showed that there were no observed changes in water levels around Banten and Lampung. Nearly one and a half-hour after the warning was issued, it was cancelled by Indonesian BMKG. == Casualties ==