Taal Volcano

A lake has an island in it. That island has a lake. That lake has a tiny island!

Volcanoes made all of it.

In the center of Volcano Island, the Main Crater Lake fills the old crater floor, and one rocky piece of that floor still pokes out. So there is an island in a lake, on an island, in a lake. NASA says it is among the world's largest islands of this kind.

Scientists at the University of the Philippines say Taal Lake was once part of Balayan Bay, an arm of the sea, until eruptions cut it off. Its water was salty in the late 1500s and slowly became fresh.

Main Crater Lake fills the old crater floor, from which one rocky remnant still emerges: an island in a lake on an island in a lake on an island, which NASA calls among the world's largest of its kind. After the January 2020 eruption the crater lake dried up for a time and refilled by March 2020 (UPRI).

UPRI: scientific evidence indicates the caldera lake was part of Balayan Bay before eruptions separated it from the sea; its water was notably salty in the late 16th century and, isolated as a catchment, became fresh. UPRI classes Taal Lake as a caldera and Volcano Island as a cone-maar complex on the Luzon-Bataan-Mindoro Arc.

Taal erupts from time to time. Scientists watch it closely.

Sometimes steam and ash shoot high into the sky.

NASA says all recorded eruptions of Taal have come from Volcano Island. In September 1965 a strong two-day eruption hit the island's southwest side, and in January 2020 an eruption sent a plume of steam, gas and ash 10 to 15 kilometers high.

The Philippine volcano agency, PHIVOLCS, uses alert levels to show how active Taal is.

The September 1965 eruption on the southwest side rated VEI 4; Binintiang Malaki, the largest flank cone, formed in 1707 (VEI 2), and smaller 1970s explosions reshaped the 1965 crater (NASA). The 12 January 2020 eruption sent a plume of steam, gas and tephra 10-15 km high (VEI 4), with further activity in 2021, 2022 and 2024 (UPRI).

PHIVOLCS raised the alert level to 2 (on a 0-5 scale) in April 2011 after rising seismicity and lake temperature, and lowered it that July (NASA).

Some fish in Taal Lake once lived in the sea.

The tawilis is a sardine that lives only in this lake.

When Taal Lake was cut off from the sea and slowly turned fresh, many sea creatures adapted. UPRI says some became freshwater kinds found only in the lake.

One is the tawilis, which UPRI calls the only freshwater sardine in the world. Another is the maliputo, a freshwater form of a sea fish called talakitok.

As the lake became fresh, many marine creatures adapted, eventually becoming freshwater variants exclusive to it (UPRI). These endemic forms include the tawilis (Sardinella tawilis), described by UPRI as the only freshwater sardine in the world, and the maliputo (Caranx ignobilis), the freshwater variant of a saltwater fish known locally as talakitok.

The island's slopes, as the photo shows, are green with plants and patches of fields.

Volcanoes can be dangerous.

Always listen to the grown-ups in charge and to safety warnings.

Taal is one of the Philippines' most active volcanoes, so its alert level can change. The CDC says to follow the advice of local officials about volcanoes, and to be ready to leave the area or take shelter if they say so.

PlayOwl's advice: on boats, wear a life jacket and stay close to your grown-up. The CDC says children near water need close, constant supervision.

CDC volcano guidance: follow local officials' advice on preparing for an eruption and, if necessary, on evacuating or sheltering; make a plan for both. CDC drowning guidance: drowning happens in seconds and is often silent; children need close and constant supervision near water.

PlayOwl's advice: check PHIVOLCS alert levels before any visit and obey closures.