Ernesto Agnir, science researcher of the Phivolcs office in Pasuquin town, said the earthquake struck at 4:26 p.m., with its epicenter located at 117 kilometers northeast of this city.
A Phivolcs bulletin issued at 5:18 p.m. Sunday, however, placed the earthquake's strength at magnitude 6.1.
While no one was reported hurt, Agnir said some residents of Laoag felt dizzy due to the ground shaking.
The earthquake was felt at Intensity 5 in this city and the towns of Pasuquin and Pagudpud; Intensity 4 in Paoay, Ilocos Norte, and Calayan Island in Cagayan; Intensity 3 in the towns of Basco in Batanes, Sinait in Ilocos Norte and Camalaniugan and Gonzaga in Cagayan; and Intensity II in Baguio City.
(Intensity 5, according to Phivolcs, means almost everybody feels the movement and the shaking may be strong enough to awaken sleeping people. Intensity 4 means most people inside their houses feel the shaking and objects are moved by the shaking. Intensity 3 means many people inside their houses or buildings feel the movement and hanging objects can be seen swaying. Intensity 2 means people resting would feel the movement.)
It was the second moderate quake that hit Ilocos Norte in 10 days. On March 10, a magnitude 5.2 quake hit Laoag and its nearby areas. That tremor's epicenter was located 101 km northeast of this city.
On February 18, a magnitude 5 tremor shook Baguio City and nearby areas, a day after three mild earthquakes – recorded at magnitudes 3.3, 3.1 and 3 – struck the summer capital and its neighboring towns.
No one was reported hurt in those earthquakes but the ground shaking, especially in the morning of February 18, woke up many Baguio residents.