The active Taal Volcano in the Philippines violently erupted on Sunday, launching ash and steam several km high in the atmosphere, causing ash-fall in surrounding heavily populated areas. Two volcanic earthquakes of magnitudes 2.5 and 3.9 were felt in Tagaytay City and Alitagtag; many more minor ones have been detected for a total of 75 volcanic earthquakes in Taal region as of 5:00 AM, January 13, 2020. This is likely a precursor to more violent eruptions in the next few days.
The Philippine Institute of Volcanology and Seismology (PHIVOLCS) raised the status of the Taal Volcano to Alert Level 4 late Sunday, indicating a hazardous eruption is imminent, and can occur within hours or over the next few days. The volcano was at an Alert Level 1 on Sunday afternoon. Alert Level 5 is issued when a hazardous eruption is in progress.
Flights at Manila’s international airport have been suspended temporarily. Residents in nearby towns, within 14 km radius, have been ordered to evacuate. Schools have been canceled in Manila and other provinces for Monday. The falling ash is a severe health hazard; besides smoke and dust that can cause respiratory problems, the ash is generally accompanied by aerosols that contain hydrochloric acid and sulfates.
Earthquakes
The following is a list of earthquakes in the region surrounding the Taal volcano (Batangas and Cavite provinces). The earthquakes started in earnest around Jan 12 13:00 and seem to have maintained a steady rate over the past 12 hours, although the average magnitude has come down a bit.
Note that each whole number increase in magnitude corresponds to an increase of about 31.6 times the amount of energy released. Earthquakes below magnitude 4 rarely cause damage. Earthquakes around magnitude 5 can cause damage to weak structures.
The Taal Volcano and Lake Taal
Taal volcano is the second most active volcano in the Philippines and has produced some of its most powerful historical eruptions. It is part of the Pacific Ring of Fire. There have been 33 recorded eruptions at Taal since 1572. Taal Volcano's greatest recorded eruption occurred in 1754 and lasted from May 15 to December 1. The last major activities on the volcano were the phreatic eruptions of 1976 and 1977
Taal lies just 50 km south of the capital city of Manila, on an island within Lake Taal.
The Taal lake area is very picturesque and a popular tourist destination.
Geology
The Taal volcano caldera lies inside an island in the Taal lake. The 25 x 18 km Lake Taal is itself a caldera filled with water, whose surface lies only 3 m above sea level.
Taal lake is located in the Luzon island of the Phillipines. Moreover, the Taal volcano caldera contains Vulcan Point, a small rocky island that projects from the surface of the crater lake. So, Vulcan Point is an island in a lake, in an island in the Taal lake, in the Luzon island in the Phillipine Sea!
Here is an aerial view of the island. Taal consists of multiple stratovolcanoes, conical hills, and craters of various shapes and sizes, spread across the island. The main caldera is the water filled cavity near the top of the picture. The 263m tall cone Binintiang Malaki (seen near the bottom) was formed during an eruption in 1707.
Some more info on the geological history of —
- Taal Volcano is part of a chain of volcanoes formed by the subduction of the Eurasian Plate underneath the Philippine Mobile Belt.
- Explosive eruptions between 140,000 and 5,380 BP created a caldera which today is seen as Taal Lake, 25 x 18 km across.
- Since the formation of the caldera, subsequent eruptions created the volcanic island within the caldera, known as Volcano Island, about 8 km at its maximum length.
- The island consists of different overlapping cones and craters of which 47 have been identified.
- The center of the island contains the crater lake, 2 km wide, formed from the 1911 eruption.
The current eruption is classified as a phreatic eruption, which occurs when magma heats ground water or surface water. The extreme temperature of the magma (anywhere from 500 to 1,170 °C) causes explosive conversion of water to steam, resulting in a high velocity ejection of steam, water, ash and rock. At Mount St. Helens in Washington state, hundreds of steam explosions preceded a 1980 eruption of the volcano.
The Philippine islands lie along the Ring of Fire, the large 40,000 km horseshoe shape line, caused by shifting of earth’s tectonic plates, which has more than 75% of the world's active and dormant volcanoes.
Images of the Eruption
Several spectacular images of the eruption are being posted online, in this day and age of smartphones. Nature, in its fire and fury, can put on a beautiful display — beautiful, at least to those watching from a far distance.
Some spectacular images and videos have been posted of lightning within the rising volcanic plume. Volcanic lightning arises from colliding, fragmenting particles of volcanic ash (and sometimes ice), which generate static electricity within the volcanic plume.
Some videos -
There is no joy for those in the fallout area of the eruption. Falling ash and acid aerosols are hazardous to health and safety, and can be lethal for the young and the elderly.
A night of terror for many. With more to come.
Volcanoes and Climate Change
One can generally say that volcanoes can cause climate change, but not the other way around; after all, they are associated with geological processes within the earth.
Volcano eruptions can cause human and climate disruption. Volcanic eruptions inject ash and sulfuric aerosols high into the atmosphere, which can reduce the amount of solar radiation reaching the Earth's surface, lower temperatures in the troposphere, disrupt the ozone layer, cause forest fires and change atmospheric circulation patterns. On the other hand, volcano eruptions inject CO2 into the atmosphere, which we know causes global warming. Of course the effects depend on the size of the eruptions. Overall, volcanoes make a relatively small contribution to atmospheric CO2, compared to humans and other sources. Large wildfires, such as the one in Australia, have similar effects on global climate.
Rising sea levels, caused by climate change, are likely to shift population centers closer to such volcanoes, with a corresponding risk of higher death tolls and injuries.
However, scientists have been studying the effect of global warming on volcanism and have detected some correlations. In the article “Get Ready for More Volcanic Eruptions as the Planet Warms” at www.scientificamerican.com/…, the authors of a study from 2017 show the correlation between glacial ice build-up and melting and decreased/increased volcanism and explain the science behind the findings -
When glaciers expand, all that ice puts immense pressure on Earth’s surface. “It can affect magma flow and the voids and gaps in the Earth where magma flows to the surface as well as how much magma the crust can actually hold,” Swindles says. When glaciers retreat, the pressure lifts and volcanic activity surges. “After glaciers are removed the surface pressure decreases, and the magmas more easily propagate to the surface and thus erupt,”
The study was based in Iceland, which has both volcanoes and glaciers on the landmass. It does not implicate volcano eruptions in the Pacific ring of fire. The authors also note that there is a significant lag (600+ years) between climate events and changes in eruption frequency.
Epilogue
2020 has so far been off to a very rough start — when it comes to weather and natural disasters. This comes on the heels of other disasters this year, like the Australian bushfires, floods in Indonesia, deadly earthquakes in Puerto Rico, heavy rains in east Africa, Angola and Israel and severe weather in the South yesterday. Never mind the man-made disasters created by the WH and the downing of the Ukrainian airliner.
Volcano eruptions in this part of the world, which is part of the Pacific ring of fire, are common. But each eruption brings a new level of death and destruction to humans, who live in their vicinity, in spite of the known dangers. For example, many poor people live on the island, even though permanent settlement on the island is prohibited, risking their lives, earning a living by fishing and farming crops from the rich volcanic soil.
Let’s pray and hope that the advanced warnings will help reduce death and destruction, which is likely to follow in the next few days. Let’s pray that the volcano is just “blowing off some steam” and will go quiet again.
Updates
Strombolian eruptions are mild volcanic eruptions and consist of ejection of incandescent cinders, lapilli, and lava bombs, to altitudes of tens to a few hundreds of metres. en.wikipedia.org/…
Not sure what this signifies for Taal.
Two relatively strong earthquakes. Over 52 earthquakes have been detected in the Taal region.
Update from PHIVOLCS-DOST — evacuations ordered within 14-km radius (was 10 km earlier) -
Monday the 13th brings ash hell -