Over 300 flights cancelled following series of eruptions on Anak Krakatoa.

Over 300 flights have now been cancelled since Anak Krakatoa, a volcanic island located in the Sunda Strait between Sumatra and Java, began erupting on Friday 4 September 2026. The volcano has produced a series of volcanic columns, some of which have reached over 15 000 m above sealevel. This has led to ash falls across the region, with all flights from Soekarno-Hatta International Airport in Jakarta, which is a little over 100 km to the east of the volcano, being cancelled. The Indonesian Ministry of Health is recommending people avoid going outside without dust masks due to the health hazard presented by the ash, which can cause severe breathing problems, and fishing fleets in the area are reportedly avoiding going to sea because of the poor conditions.

Drone footage of an ash column emerging from Anak Krakatoa on Saturday 5 September 2026. Reuters.

Volcanic ash is extremely hazardous to aircraft in a number of ways. At its most obvious it is opaque, both visually and to radar. Then it is abrasive, ash particles physically scour aircraft, damaging components and frosting windows. However the ash is most dangerous when it is sucked into jet engines, here the high temperatures can melt the tiny silica particles, forming volcanic glass which then clogs engine. When this happens the only hope the aircraft has is to dive sharply, in the hope that cold air passing through the engine during the descent will cause the glass to shatter, allowing the engine to be restarted. Obviously this is a procedure that pilots try to avoid having to perform.

Anak Krakatau is a volcanic island located in the Sunda Strait between Sumatra and Java. The volcano (then known simply as Krakatoa) famously exploded in 1883, killing over 36 000 people (possibly over 120 000), largely through a series of tsunamis. This explosion more-or-less completely destroyed the island, but since then a new volcano, Anak Krakatau (meaning the 'son of Krakatoa'), has grown in its place. Anak Krakatau is almost never completely quiet, but goes through periods of greater and lesser activity. An eruption on 22 December 2018 triggered a tsunami which tsunami caused over 430 fatalities, injured 14 000 people, and displaced 33 000 more along the Sunda Strait. The tsunami risk of this area is particularly high as the coast is very popular with both locals and tourists and is home to over 20 million people within a 100 km distance from the volcano.

Anak Krakatau is located to the north of the Sunda Trench, along which the Australian Plate is being subducted beneath the Sunda Plate, on which the island sits. As the Australian Plate is subducted it is partially melted by the friction and the heat of the planet's interior. Some of this melted material then rises through the overlying Sunda Plate, fuelling Krakatau and the volcanoes of Sumatra and Java.

The Subduction zone beneath Sumatra. NASA/Earth Observatory.

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Authorities in Singapore seize largest ever shipment of Rhinoceros horn.

A consignment of 20 Rhinoceros horns weighing 35.7 kg and with an estimated value of US$870 000 has been seized at Singapore Changi Airport, according to a press release issued by the Singapore National Parks on 18 November 2025. The consignment was discovered on 8 November by Vengadeswaran Letchumanan, an employee of air cargo handling company SATS, who noticed a strange smell coming from a package labelled 'furniture fittings' which was being shipped from South Africa to Laos.

Rhinoceros horns seized at Singapore Changi Airport on 8 November 2025. Singapore National Parks.

Concerned by the smell, Mr Vengadeswaran, contacted his line manager, who intern contacted SATS Security, who opened the package. Upon discovering the contents of the first package, three other packages from the same consignment were X-rayed, revealing similar contents. As well as the Rhinoceros horns, the packages contained 150 kg of other Animal parts, which have yet to be identified, including bones, teeth and claws.

Animal parts seized at Singapore Changi Airport on 8 November 2025. Singapore National Parks.

The Rhinoceros horns have been identified by the Centre for Wildlife Forensics as having originated from White Rhinoceros, Ceratotherium simum, a species currently listed as Near Threatened on the International Union for the Conservation of Nature's Red List of Threatened Species. The international trade in Rhino horn was banned in 1977 under the terms of the Convention on International Trade in Endangered Species, to which Singapore is a signatory.

South Africa is home to more than half of the world's surviving Rhinoceros population, but has (like many other countries) faced significant problems from poaching of the Animals for their horns. This reached a peak between 2013 and 2017, with more than a thousand Rhinos being killed each year in South Africa, according to Save the Rhino, although the number fell each year from 2015 until 2020. During the COVID 19 pandemic there was an increase in poaching, with the number killed rising slowly each year until 2023. There was a drop of about 15% in 2024, although this still resulted in 420 known Rhinoceros poaching incidents. The majority of Rhino poaching is thought to be carried out by organised crime syndicates, rather than opportunistic local hunters. 

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At least 116 dead as Typhoon Kalmaegi sweeps across the Philippines.

At least 116 people are now known to have died, with many more still missing, after Typhoon Kalmaegi swept across the central Philippines on Tuesday 4 November 2025. The majority of the deaths occurred in the city of Cebu, and surrounding metropolitan area, with 35 people having apparently drowned in a single incident in the town of Liloan, with 76 people having died in the greater metropolitan area, despite over 400 000 being evacuated from areas deemed to be at risk ahead of the storm. On Mindanao Island a military helicopter taking part in relief efforts crashed during the storm, leading to the deaths of all six crewmembers.

Damage in the city of Talisay on Cebu Island following the passage of Typhoon Kalmaegi on 4 November 2025. Jam Sta Rosa/AFP/Getty Images.

On Negros Island at least 12 people have died and 12 more are still missing after heavy rains triggered a lahar, which buried a number of homes in Canlaon City. Lahars are ash-laden flash floods associated with volcanoes. They can be caused directly by volcanic eruptions, for example when hot lava encounters a glacial lake rapidly destroying an ice dam, but are also common in areas of high seasonal rainfall, where ash deposits from a volcano can build up during the dry season, creating dams on seasonal waterways, which temporarily halt the flow of water, then give way rapidly leading to dramatic flash floods. The Negtos lahar was caused by heavy rains associated with Typhoon Kalmaegi falling onto unconsolidated ash from an eruption on Mount Kanloan last year.

Tropical storms are caused by the warming effect of the Sun over tropical seas. As the air warms it expands, causing a drop in air pressure, and rises, causing air from outside the area to rush in to replace it. If this happens over a sufficiently wide area, then the inrushing winds will be affected by centrifugal forces caused by the Earth's rotation (the Coriolis effect). This means that winds will be deflected clockwise in the northern hemisphere and anti-clockwise in the southern hemisphere, eventually creating a large, rotating Tropical Storm. They have different names in different parts of the world, with those in the northwest Pacific being referred to as typhoons.

The structure of a tropical cyclone. Wikimedia Commons.

Despite the obvious danger of winds of this speed, which can physically blow people, and other large objects, away as well as damaging buildings and uprooting trees, the real danger from these storms comes from the flooding they bring. Each drop millibar drop in air-pressure leads to an approximate 1 cm rise in sea level, with big tropical storms capable of causing a storm surge of several meters. This is always accompanied by heavy rainfall, since warm air over the ocean leads to evaporation of sea water, which is then carried with the storm. These combined often lead to catastrophic flooding in areas hit by tropical storms. 

The formation and impact of a storm surge. eSchoolToday.

Typhoon Kalmaegi, known as Typhoon Tino in the Philippines, deposited 183 mm of rain onto Cebu Island in the 24 hours before making landfall. When it arrived, it brought with it sustained winds of more than 130 km per hour, with gusts exceeding 180 km per hour. Storms such as this are becoming more frequent due to global warming which is warming the oceans faster than the land, with the Philippines, which typically suffers about 20 storms per year, having been hit by twelve major storms since the typhoon season began in June this year: Tropical Storm Wutip in June, Typhoon Danas, Severe Tropical Storm Wipha, and Severe Tropical Storm Co-May in July, Tropical Depression Fabian and Typhoon Kajiki in August, Tropical Storm Mita, Typhoon Ragasa, and Typhoon Bualoi in September, and Typhoon Matmo, Severe Tropical Storm Fengshen, and Tropical Depression Salome in October. Furthermore, it is thought likely that a system currently known as Tropical Depression Thirty Two, which is currently crossing the central Pacific, will increase in strength and become a Typhoon-strength storm before making landfall in the Philippines this weekend.

A rescue team in the Talamban District of Cebu City following the passage of Typhoon Kalmaegi on 4 November 2025. Philippine Red Cross/Reuters.

As well as leading to larger and more frequent storms, warmer seas can enable them to change course rapidly, making it harder to predict where and when they will make landfall. However, this does not appear to have been the issue in the Philippines this week, where over half a million people were evacuated in advance from areas considered vulnerable to the storm. Instead, the storm has contributed to a growing corruption scandal in the country, with approximately 26.6 billion Philippine Pesos (about US$452 million) having been spent on flood defences which were found to be insufficient, incomplete, or simply absent as the storm approached.

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Warning to aviation issued following eruption on Mount Shishaldin, Alaska.

The US National Weather Service has issued a warning to aviation following an eruption on Mount  Shishaldin, a 2870 m stratovolcano (cone-shaped volcano made up of layers of ash and lava), located on Unimak Island in the Aleutian Island Chain, on Friday 14 July 2023. The volcano began erupting on Tuesday 11 July, but did not produce any major distuprion until slightly before 1.10 am local time onl Friday, when a large explosive eruption produced an ash cloud which rose to over 12 000 m above sealevel. A second eruption at about 7.10 am produced a smaller ash cloud, which on this occasion rose to about 4500 m. 

A plume of volcanic ash above Mount Shishaldin at a 10.33 am local time on Friday 14 July 2023. Matt Loewen/Alaska Volcano Observatory/United States Geological Survey/AP.

Volcanic ash is extremely hazardous to aircraft in a number of ways. At its most obvious it is opaque, both visually and to radar. Then it is abrasive, ash particles physically scour aircraft, damaging components and frosting windows. However, the ash is most dangerous when it is sucked into jet engines, here the high temperatures can melt the tiny silica particles, forming volcanic glass which then clogs engine. When this happens the only hope the aircraft has is to dive sharply, in the hope that cold air passing through the engine during the descent will cause the glass to shatter, allowing the engine to be restarted. Obviously, this is a procedure that pilots try to avoid having to perform.

Mount Shishaldin is the westernmost of three volcanoes located in an east-west line across Unimak Island. It is the largest volcano in the Aleutian Islands, and considered to be coincided to be the most symmetrical volcano on Earth, with contour lines forming near perfect circles, although the north and south slopes are steeper than the east and west slopes. The current cone structure of Mount Shishaldin is thought to be less than 10 000 years old, and is built on the remnants of an older cone, which is exposed to the west and northeast sides. To the northwest of the main volcano is an area of massive lava flows, with 24 smaller cones, thought to be parasitic on the main volcano.

The position of Mount Shshaldin on Unimak Island. Google Maps.

The volcanoes of the Alaskan Peninsula and Aleutian Islands are fed by magma rising from the Pacific Plate, which is being subducted beneath the North American Plate to the south along the Aleutian Trench. As the subducting plate sinks into the Earth, it is subjected to enormous heat and pressure, causing more volatile minerals to melt. These then rise through the overlying North American plate as magma, fuelling the Alaskan volcanoes.

How the subduction of the Pacific Plate beneath the North American Plate fuels the volcanoes of Alaska. Alaska Volcano Observatory.

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Eruption on Mount Popocatépetl closes airports in Mexico City.

An eruption on Mount Popocatépetl led to a major ashfall affecting Mexico City in the early hours of Saturday 20 May 2023, which in turn closed the city's two airports to close. Volcanic ash is extremely hazardous to aircraft in a number of ways. At its most obvious it is opaque, both visually and to radar. Then it is abrasive, ash particles physically scour aircraft, damaging components and frosting windows. However, the ash is most dangerous when it is sucked into jet engines, here the high temperatures can melt the tiny silica particles, forming volcanic glass which then clogs engine. When this happens the only hope the aircraft has is to dive sharply, in the hope that cold air passing through the engine during the descent will cause the glass to shatter, allowing the engine to be restarted. Obviously, this is a procedure that pilots try to avoid having to perform. Communities closer to the volcano were also affected by the ashfall, with eleven schools being closed as a precaution due to poor air quality, although there are no reports of any damage or casualties.

An eruption on Mount Popocatépetl slightly before midnight on Friday 19 May 2023. Webcams de Mexico.

Popocatépetl has been more or less constantly erupting since the mid 1990s, but most of the time this activity remains at a low level. Major eruptions on Popocatépetl are a cause for concern as the volcano is in a densely populated area, with 30 million people living within the potential hazard zone. The last major eruption, a Plinian (or Vesuvian) event in about 800 AD, triggered a series of pyroclastic flows and lahars that scoured the basins around the volcano.

The location of Mount Popocatépetl. Google Maps.

The volcanoes of the Trans-Mexican Volcanic Belt (including Popocatépetl) are fuelled by the subduction of the Cocos Plate beneath the North American Plate along the Middle American Trench to the south of Mexico. As the subducting plate sinks into the Earth it is melted by the heat and pressure, and volatile minerals liquefy and rise through the overlying North American Plate as magma, fueling Mexico's volcanoes. 

The subduction of the Cocos Plate beneath the North American Plate in Mexico, and how it leads to volcanoes and Earthquakes. King Saud University.

The Cocos Plate is thought to have formed about 23 million years ago, when the Farallon Plate, an ancient tectonic plate underlying the East Pacific, split in two, forming the Cocos Plate to the north and the Nazca Plate to the south. Then, roughly 10 million years ago, the northwesternmost part of the Cocos Plate split of to form the Rivera Plate, south of Beja California.

The position of the Cocos, Nazca and Rivera Plates. MCEER/University at Buffalo.

In a paper published in the Journal of Geophysical Research: Solid Earth, in 2011, a team led by Igor Stubailo of the Department of Earth and Space Sciences at the University of California Los Angeles, published a model of the subduction zone beneath Mexico using data from seismic monitoring stations belonging to the Mesoamerican Seismic Experiment, the Network of Autonomously Recording Seismographs, the USArray, Mapping the Rivera Subduction Zone and the Mexican Servicio Sismologico Nacional.

 

The seismic monitoring stations were able to monitor not just Earthquakes in Mexico, but also Earthquakes in other parts of the world, monitoring the rate at which compression waves from these quakes moved through the rocks beneath Mexico, and how the structure of the rocks altered the movement of these waves.

Based upon the results from these monitoring stations, Stubailo et al. came to the conclusion that the Cocos Plate was split into two beneath Mexico, and that the two plates are subducting at different angles, one steep and one shallow. Since the rate at which a plate melts reflects its depth within the Earth, the steeper angled plate melts much closer to the subduction zone than the shallower angled plate, splitting the Trans-Mexican Volcanic Belt into sections above the different segments of the Cocos Plate, and causing it to apparently curve away from the subduction zone.

Top the new model of the Cocos Plate beneath Mexico, split into two sections (A & B) subducting at differing angles. (C) Represents the Rivera Plate, subducting at a steeper angle than either section of the Cocos Plate. The Split between the two has been named the Orozco Fracture Zone (OFZ) which is shown extended across the Cocos Plate; in theory this might in future split the Cocos Plate into two segments (though not on any human timescale). Bottom Left, the position of the segments on a map of Mexico. Darker area is the Trans-Mexican Volcanic Belt, orange circles are volcanoes, brown triangles are seismic monitoring stations, yellow stars are major cities. Bottom Right, an alternative model showing the subducting plate twisted but not split. This did not fit the data. Stubailo et al. (2012).

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