Magnitude 7.4 Earthquake off the coast of Mindanao Island, Philippines.

The Philippine Institute of Volcanology and Seismology recorded a Magnitude 7.4 Earthquake at a depth of 23 km about 48 km to the northeast of  the town of Manay in Davao Oriental Province on Mindanao Island, Philippines, slightly before 9.45 am local time (slightly before 1.45 am GMT) on Friday 10 October 2025. At least seven people have been reported dead following the Earthquake, including a woman struck by falling debris and two patients who suffered heart attacks in hospitals. A large number of buildings have been damaged, including a hospital, and several hundred people are reported to have been injured. The event  was felt across the southeastern Philippines, and triggered a tsunami warning in parts of the Philippines and Japan, although in the event no major wave damage occurred. The initial event has been followed by a series of large aftershocks, some of which have had magnitudes in excess of 6.0.

The location of the 2 December 2023 Mindanao Earthquake. USGS.

The geology of the central Philippines is Complex. The west of Mindanao Island is located on the Banda (or Sunda) Microplate, and the east on the Philippine Plate, which is being subducted beneath the Sunda (or Banda) Microplate along the central part of the island. Immediately to the east of the Island the Pacific Plate is being subducted along the Philippine Trench, and passes beneath eastern Mindanao as it sinks into the Earth. This is not a smooth process, an the plates constantly stick together then break apart again as the pressure builds up, resulting in Earthquakes.

Subduction beneath the Philippines. Yves Descatoire/Singapore Earth Observatory.

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At least 28 people have died in flooding and landslides associated with Tropical Storm Raymond in Mexico.

At least 28 people have died in Mexico on Thursday 9 and Friday 10 October 2025, as Tropical Storm Raymond has moved up the east coast of the country. Thirty one of the country's thirty two states have been affected by storm-related incidents, although the State of Hidalgo, to the north of Mexico City, has been the worst hit, with several rivers bursting their banks due to high rainfall, leading to 16 known deaths, and more than a thousand homes, as well as 59 medical centres and 308 schools, being impacted by flooding. A further nine deaths have been reported in the neighbouring State of Puebla, which lies to the south and east of Mexico city, with another thirteen people missing, and a gas pipeline fractured by a landslide. In the State of Veracruz, on the coast to the east of Hidalgo and Pueblo, at least two people have died, including a police officer and  child caught in a landslide.

Flooding in Veracruz State, Mexico, this week. Marco Antonio Perez/AFP.

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. 

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.

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Batrachedra olei: A new species of Frog Moth from La Gomera, Canary Islands.

Frog Moths, Batrachedridae are a small group of largely tropical Moths, which gain their name from their resting posture, in which the front legs are held under the body while the back legs sprawl at the side, causing them to sit upright in a similar manner to a Frog. There are ten genera within the Family Batrachedridae, with the most abundant genus, Batrachedra, containing 114 known species and being found on every continent except Antarctica.

In a paper published in the journal SHILAP Revista de lepidopterología on 30 September 2025, Per Falck, an independent researcher from Neksø in Denmark describes a new species of Batrachedra, from the island of La Gomera in the Canaries. 

The new species is named Batrachedra olei in honour of the Danish lepidopterist Ole Karsholt, who Per Falck identifies as a good friend, and who helped him which both the content and the language of the research paper. The species is described from a series of specimens attracted to an actinic light (the sort of light in electric 'fly-killers') set up at locations on the island of La Gomera between 2021 and 2024.

Batrachedra olei, male, La Gomera, 11.5 mm wingspan. Falck (2025).

Specimens of Batrachedra olei range from 7.5 to 12.5 mm in wingspan, and have are white on their heads, necks, and the forepart of their thoraxes, while the hindpart of their thoraxes, their abdomens, their hindwings, and their antennae are yellowish grey. The forewings of the species are yellowish ochreous mottled with grey scales, with two indistinct, longitudinal streaks.

 Batrachedra olei, female, La Gomera, 12 mm wingspan. Falck (2025).

Adults of Batrachedra olei were found on the northern part of La Gomera between January and November, no juvenile specimens were found. The species is probably endemic to the island. Batrachedra olei is the first species discovered in the Canary Islands. There are seven previously described species of Batrachedra from Europe and North Africa, but a DNA barcode analysis recovered an unnamed species from South Africa as the closest relative to Batrachedra olei.

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Eighteen dead after bus hit by landslide in Himachal Pradesh, India.

Eighteen people have died and several more have been injured after a landslide hit a bus in the Bilaspur District of Himachal Pradesh, India, on Tuesday 7 October 2025. The incident happened at about 6.30 pm local time, with a large section of the side of a hill giving way following days of heavy rain, and sweeping the bus, which held between 30 and 35 people at the time, from the road. Landslides are a common problem after severe weather, as excess pore water pressure can overcome cohesion in soil and sediments, allowing them to flow like liquids. Approximately 90% of all landslides are caused by heavy rainfall.

Rescue workers searching for survivors after a landslide swept a bus from a road in Himachal Pradesh State, India, on Tuesday 7 October 2025. National Disaster Response Force/Associated Press.

Mountainous areas of Himachal Pradesh (which is most of the state) are notoriously prone to landslides, particularly during the monsoon season, which typically lasts from July to September, when very high rainfall levels can trigger many such events. Years such as this year, in which the monsoon lasts longer, are particularly dangerous, as the ground will have become waterlogged, and unable to absorb any more rain, leading to an increased risk of landslide and flood events. Sadly, while late rains were once a rare event, they are becoming more common as a result of global warming, which is resulting in a hotter, wetter climate in the region.

Monsoons are tropical sea breezes triggered by heating of the land during the warmer part of the year (summer). Both the land and sea are warmed by the Sun, but the land has a lower ability to absorb heat, radiating it back so that the air above landmasses becomes significantly warmer than that over the sea, causing the air above the land to rise and drawing in water from over the sea; since this has also been warmed it carries a high evaporated water content, and brings with it heavy rainfall.

In the tropical dry season, the situation is reversed, as the air over the land cools more rapidly with the seasons, leading to warmer air over the sea, and thus breezes moving from the shore to the sea (where air is rising more rapidly) and a drying of the climate. This situation is particularly intense in South Asia, due to the presence of the Himalayas. High mountain ranges tend to force winds hitting them upwards, which amplifies the South Asian Summer Monsoon, with higher winds leading to more upward air movement, thus drawing in further air from the sea.

Diagrammatic representation of wind and rainfall patterns in a tropical monsoon climate. Geosciences/University of Arizona.

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Asteroid 2025 TC passes the Earth.

Asteroid 2025 TC passed by the Earth at a distance of 85 271 km (22% of the average distance between the Earth and the Moon, or 0.000 57% of the distance between the Earth and the Sun, but more than 200 times the altitude at which the International Space Station orbits, and more than double the distance at which geostationary satellites orbit), with a relative velocity of about 16.15 km per second, slightly before 6.35 am GMT on Friday 3 October 2025. 

The relative positions of 2025 TC, the Earth, and the Moon at 6.00 am on Friday 3 October 2025. JPL Small Body Database.

There was no danger of the asteroid hitting us, though were it to do so it would not have presented a significant threat. 2025 TC has an estimated equivalent diameter of 7-23 m (i.e. it is estimated that a spherical object with the same volume would be 7-23 m in diameter), and an object of this size would be expected to explode in an airburst (an explosion caused by superheating from friction with the Earth's atmosphere, which is greater than that caused by simply falling, due to the orbital momentum of the asteroid) more than 20 km above the ground, with only fragmentary material reaching the Earth's surface.

2025 TC was first detected on 1 October 2025 (two days before its closest approach to the Earth), by the University of Hawaii's PANSTARRS telescope. The designation 2025 implies that it was the third asteroid (asteroid C - in numbering asteroids the letters A-Z, excluding I, are assigned numbers from 1 to 25, with a number added to the end each time the alphabet is ended, so that A = 1, A1 = 25, A2 = 49, etc., which means that C = 3) discovered in the first half of October 2025 (period 2025 T; the year being split into 24 half-months represented by the letters A-Y, with I being excluded).

2025 TC is calculated to have a 1604 day (4.39 year) orbital period, with an elliptical orbit tilted at an angle of 1.92° to the plain of the Solar System which takes in to 0.80 AU from the Sun (80% of the average distance at which the Earth orbits the Sun) and out to 4.57 AU (4.57 times the distance at which the Earth orbits the Sun, more than three times the distance at which the planet Mars orbits). As an asteroid that is on average further from the Sun than the Earth, but which does get closer, 2025 is classified as an Apollo Group Asteroid.

The relative positions of 2025 TC and the planets of the Inner Solar System at 6.00 am on Friday 3 October 2025. JPL Small Body Database.

This means that 2025 TC has occasional close encounters with the Earth, with the last thought to have happened in September 1978 Venus, which it last cam close to in January 2008 and is next predicted to pass in June 2084, and Venus, which it last came close to in March 1967, Mars, which it last came close to in November 1955, and Jupiter, which it last came close to in July 2019.

Asteroids which make close passes to multiple planets are considered to be in unstable orbits, and are often eventually knocked out of these orbits by these encounters, either being knocked onto a new, more stable orbit, dropped into the Sun, knocked out of the Solar System or occasionally colliding with a planet. In the case of 2025 TC, it is predicted that it will have another close encounter with Jupiter in October 2054, which will knock it onto an orbit which no longer comes close the planets of the Inner Solar System.

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