FALSE: Low tide in Oriental Mindoro sign of possible volcanic tsunami

Claim: Facebook page Philippine Weather System/Earthquake Update claimed on Monday, January 13, that the supposed unusual low tide in Barangay Lumangbayan in the town of San Teodoro, Oriental Mindoro is a sign of a possible volcanic tsunami. 

A part of the caption reads, “Guys ingat para sa lahat. Not a typical type of low tide. Kita ang mga coral reefs. Since ang San Teodoro Or. Mdo. malapit sa Batangas, probably nahigop ang tubig because ng Taal, so once mag erupt ang bulkan, babalik ang tubig nyan.. So please be safe at handa ang lahat sa possible na Vulcanic Tsunami.”

(Stay safe, guys. It’s not a typical low tide. The coral reef appeared. Since San Teodoro Oriental Mindoro is near Batangas, probably its water was drawn by Taal [Volcano]. Once the volcano erupts, the water will return. So please be safe for the possible volcanic tsunami.)

The caption is accompanied by photos of scattered fish washed ashore due to receding seawater in the province on the days when Taal erupted. The photos are credited to a certain Atoms Ki Tilaram. 

The claim was spotted by readers and was sent to Rappler’s email for verification. Using the social media tool CrowdTangle, Rappler spotted at least 3 other pages that shared the same claim. The total interaction from these pages accumulated over 21,700 shares, 25,100 reactions, and 2,300 comments. 

Rating: FALSE

The facts:  According to the Philippine Institute of Volcanology and Seismology (Phivolcs), it is “almost unlikely” for low tide in Oriental Mindoro to be connected to a potential volcanic tsunami that is related to Taal Volcano’s eruption.

“Kung magkakaroon ng low tide [sa Mindoro], most likely hindi about sa Taal (If a low tide occurs [in Mindoro], it is most likely not connected to Taal),” Lincoln Olayta, research specialist I of Phivolcs told Rappler in a phone interview.

He explained that a volcanic tsunami is caused by a “debris fall” or “landslide” inside the volcano. The possibility of a volcanic tsunami, he added, arises when the volcano experiences an explosive eruption.

As of Thursday, January 15, Taal Volcano remains under Alert Level 4 after its phreatic eruption on Sunday, January 13. Based on its bulletin report released on Tuesday, Phivolcs urged those within a 14-kilometer radius from Taal’s main crater to evacuate due to a high risk of volcanic tsunami within the area. Phivolcs did not state whether a Taal eruption would trigger a tsunami in other parts of Batangas or its nearby provinces.  

Rappler also previously debunked a claim that Taal Volcano somehow draws water from the sea around Oriental Mindoro. Olayta of Philvolcs said the two bodies of water are not connected to each other.

The Mayor’s Office of San Teodoro, Oriental Mindoro also told Rappler in an email that the claim about the unusual low tide is a “baseless speculation stemming from ignorance.”

“There was a -0.5m low tide that occurred in Barangay Lumangbayan (a common occurrence) this 12th and 13th day of January and people [who] do not live in that particular barangay got alarmed because it coincided with the eruption of Taal Volcano,” they added. 

They also said that they already addressed this concern with the Department of Environment and Natural Resources (DENR) and other concerned agencies. 

The original post of Facebook user Atoms Ki Tilaram about the false tsunami alert was already taken down. However, some Facebook pages have already reposted the claim which might have caused a tsunami scare. – Glenda Marie Castro/Rappler.com

Keep us aware of suspicious Facebook pages, groups, accounts, websites, articles, or photos in your network by contacting us at factcheck@rappler.com. Let us battle disinformation one Fact Check at a time.

More fact checks on the January 2020 Taal Volcano eruption:

• FALSE: ‘Magnitude 7.8 earthquake on January 15’ after Taal eruption
• PARTLY FALSE: Mayon Volcano status ‘raised’ to Alert Level 2
• PARTLY FALSE: Pacific Ring of Fire ‘now active’
• FALSE: Kim Atienza, BBC ‘reported about phone emitting radiation’
• FALSE: ‘NDRRMC update’ on Taal Alert Level 5
• FALSE: ‘Photo’ of Taal Volcano eruption