The unusually strong sea current recorded by netizens in Soboc, Viga last Wednesday evening, about 12 hours after the 8.8-magnitude earthquake that triggered a tsunami, was attributed by local disaster management officials to “normal high tide occurrence.”
This was communicated by personnel of the Provincial Disaster Risk Reduction and Management Office (PDRRMO) when asked if the Viga MDRRMO had already conducted an investigation into the incident.
It may be recalled that several netizens uploaded on Facebool videos of the abnormal current from the sea nearly carrying a motorized banca as the onrushing sea flowed upstream into a creek beside the coastal village at 9 PM of July 30, 2025.
“Negative,” said the PDRRMO official, adding that the Viga DRRMO blamed a “false perception” on social media by netizens.
It may be recalled that the undersea temblor off the Kamchatka peninsula in Russia at 7:24 AM that day triggered a tsunami that swamped several coastal areas, with tsunami warnings raised in adjoining countries around the Pacific Ocean, including the Philippines.
The Philippine Institute of Volcanology and Seismology (PhiVolcs) subsequently issued a Tsunami Advisory soon after, warning of minor sea level disturbance with wave heights of less than one meter along coastal areas facing the Pacific, including Catanduanes, anytime between 1:20 PM and 2:40 PM that day.
It cancelled the advisory at 4:40 PM, saying that available data from sea level monitoring stations facing the Pacific Ocean did not record significant sea level disturbances up to the time of the cancellation.
“Any effects due to minor sea level disturbances have largely passed,” PhiVolcs stressed.
However, reports and videos shown on TV and online show that several tsunami waves caused by the Kamchatke earthquake arrived at the island of Oahu in Hawaii in the evening of July 30.
One CCTV footage showing the sea receding at 7:37 PM and the first wave arriving at 7:44 PM, followed by the second wave at 8:04 PM.
The waves caused minor flooding along coastal areas, including beach-side hotels and homes but did not cause any damage.
Oahu is about 4,900 kilometers from the earthquake epicenter while Soboc, Viga is about 5,300 kilometers away.
The wave would have traveled at a speed of approximately 400 kilometers per hour to reach the shores of the Hawaiian island at 8 PM.
To arrive at Soboc Bay using the same velocity, it would have reached the bay 13 hours later or at about 9 PM.
Tide times for July 30, 2025 for the Legazpi port district furnished by PAGASA to the Tribune showed high tide occurring at 9:20 PM at a height of 4.53 feet or 1.38 meters, six hours after the low tide of 0.72 feet or 0.22 meter at 3:01 PM.
The Tribune tried to access sea level records for that day at PhiVolcs’ tsunami monitoring website but data was unavailable for the Tsunami Early Warning System (TEWS) facility at the Virac port that was installed by the Japan International Cooperation Agency (JICA).
The facility, which underwent repair after it was transferred to the breakwater, sends its data to the Japan Meteorological Agency (JMA).
Data for the nearest Sea Level Monitoring Station (SLMS) of PhiVolcs at Borongan, Eastern Samar was posted at the site.
It indicated that sea level at the coastal city was at highs of 2:51 meters at 8:35 PM. 2.49 meters at 9:20 PM and 2.50 meters at 9:45 PM.
On July 31 and August 1, the highest tide level was at 2.45 meters and 2.41 meters, respectively, the same record showed.
Tribune records show that an hour after PhiVolcs lifted the tsunami warning issued in the wake of the Feb. 27, 2010 Chile 8.8-magnitude earthquake, sea level at Virac port suddenly rose by more than a meter at 5:32 PM of Feb. 28, surprising diners at the defunct Sea Breeze Restaurant.
Photos of the sea surge made the frontpage of this paper on its March 10, 2010 issue.