Magnitude 6.1 Earthquake on the east coast of Taiwan.

The Taiwan Central Weather Bureau has reported a Magnitude 6.1 Earthquake at a depth of 11.9 km, 10.1 km to the north of the city of Taitung on the east coast of Taiwan, slightly after 5.45 pm local time (slightly after 9.45 am GMT on Wednesday 24 December 2025. There are no reports of any damage or casualties following this event, but it was felt across much of the island.

The approximate location of the 24 December 2025 Taiwan Earthquake. USGS.

Taiwan has a complex tectonic setting, lying on the boundary between the Eurasian and Philippine Plates, with the Eurasian Plate being subducted beneath the Philippine Plate in the South and the Philippine Plate being subducted beneath the Eurasian in the East. Subduction is not a smooth process even in simple settings, with plates typically sticking together as pressure from tectonic expansion elsewhere builds up, then suddenly breaking apart and shifting abruptly, causing Earthquakes.

The motion of the tectonic plates beneath Taiwan. The University of Memphis.

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Ptychognathus dajie: A new species of Pom Pom Crab from East and Southeast Asia.

The genus Ptychognathus comprises 32 species of brackish-water Crabs found in estuaries and the lower parts of river systems across the Indo-Western Pacific region. They are known as Pom Pom Crabs in the aquarium industry because of the clusters of fine setae (hairs) on their claws (although they are widely traded as freshwater Crabs rather than brackish-water Crabs). Most species of Ptychognathus have very localised distributions, being found on a single island, estuary, or river system, although one species, Ptychognathus barbatus, is found over an extremely wide area, including Japan, Taiwan, China, the Philippines, Malaysia, Indonesia, and New Caledonia. However, as part of a PhD thesis completed in 2006, carcinologist Ngan Kee Ng, then a graduate student at the National University of Singapore, examined the systematics of Ptychognathus barbatus, concluding that the populations described under this name represented two, rather than a single, species. Ng went on the lead a highly successful research group, specialising in the study of Crabs, for many years, before passing away in 2022, but never formerly published her PhD thesis. This means that all taxonomic nomenclature presented in the thesis is considered unusable under the terms of the International Code of Zoological Nomenclature, even if specialists in the field believe it to be generally correct.

In a paper published in the journal ZooKeys on 27 June 2025, Jhih-Wei Hsu of the Department of Life Science at the National Chung Hsing University, Jose Christopher Mendoza, of the Lee Kong Chian Natural History Museum at the National University of Singapore, and Hsi-Te Shih, also of the Department of Life Science, and of the Global Change Biology Research Center at the National Chung Hsing University, build upon Ngan Kee Ng's work, to formally divide Ptychognathus barbatus into two, and describe a new species.

The new species is named Ptychognathus dajie, where 'dajie' means 'elder sister', a title often used for women in leadership roles in Chinese-speaking countries, in honour of Ngan Kee Ng. A genetic analysis of museum specimens suggests that this species is found in estuaries and tidally-influenced portions of rivers, in Malaysia, Japan, Taiwan, China, Philippines, Indonesia, and Thailand. Surprisingly, Ptychognathus dajie is not particularly closely-related to Ptychognathus barbatus, instead forming a sister species to Ptychognathus guijulugani, a species found on Negros and Mindanao islands in the Philippines, placing it close to the base of the Ptychognathus family tree.

A neighbor-joining tree for species of Ptychognathus, based on the COI gene. Probability values at the nodes represent support values. Only values greater than 50% are shown. Hsu et al. (2025).

Specimens of Ptychognathus dajie have almost square carapaces, slightly wider than they are long, with a glossy upper surface and a concave frontal margin. The lower part of the claw is covered by long, thin setae; claws are larger in males than in females. The largest male specimen found was 20.2 mm wide and 16.8 mm long, the largest female found was 16.8 mm wide and 14.5 mm long. Colour is extremeley variable, and tends to match the substrate upon which the Crabs live.

Ptychognathus dajie. (A), (B) Holotype male (13.2 × 11.6 mm, ZRC 2024.0072); (C), (D) Paratype female (10.6 × 9.2 mm, NCHUZOOL 17356); (E) Male (NCHUZOOL 17341); (F) Male (NCHUZOOL 17343); (G), (H) Males (NCHUZOOL 7342). (A), (C) Dorsal view; (B), (D) Ventral view; (A)–(D) Preserved specimens; (E)–(H) Colour in life. Hsu et al. (2025).

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Magnitude 7.2 Earthquake hits Taiwan, killing at least nine people.

The Taiwan Central Weather Bureau has reported a Magnitude 7.2 Earthquake at a depth of 15.5 km, about 25 km to the south of the city of Hualien, Taiwan, slightly before 8.00 am local time on Wednesday 3 April 2024 (slightly before midnight on Tuesday 2 April, GMT) on Sunday 18 September 2022. The event is reported to have killed at least nine people, with more than 900 more injured, and to have caused several buildings to collapse, as well as triggering a series of landslides. The Earthquake was felt on the Chinese mainland as far north as Shanghai and Nanjing. 

The approximate location of the 3 April 2024 Taiwan Earthquake. USGS.

The event was the largest Earthquake to hit Taiwan in 25 years, and was followed by 76 aftershocks within the next five ours, thirteen of which had Magnitudes above 5.0, with the largest being a Magnitude 6.4 event. Dozens of buildings are reported to have collapsed in city of Hualien, and landslides triggered by the Earthquake are reported to have trapped large numbers of vehicles and their occupants inside tunnels on the Suhua Highway, which runs along the east coast of the island between Yilan to Hualian.

A collapsed building in Hualien following a Magnitude 7.4 Earthquake on 3 April 2024. Taiwan National Fire Agency/Reuters.

Taiwan has a complex tectonic setting, lying on the boundary between the Eurasian and Philippine Plates, with the Eurasian Plate being subducted beneath the Philippine Plate in the South and the Philippine Plate being subducted beneath the Eurasian in the East. Subduction is not a smooth process even in simple settings, with plates typically sticking together as pressure from tectonic expansion elsewhere builds up, then suddenly breaking apart and shifting abruptly, causing Earthquakes.

The motion of the tectonic plates beneath Taiwan. The University of Memphis.

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Idioctis parilarilao: A new species of Intertidal Trapdoor Spider from Taiwan.

Spiders are one of the most diverse groups of terrestrial Arthropods, but are only rarely found in aquatic environments. Species that live in freshwater environments include the Fishing or Raft Spiders, Dolomedes spp., and the Eurasian Water Spider, Argyroneta aquatica. Spiders able to inhabit marine environments are even rarer, with examples including several members of the Family Dictynidae, Several genera of Jumping Spiders, Salticidae, a single genus each of Anyphaenid Spiders and Desid Spiders, Amaurobioides and Cambridgea, respctively, as well as some populations of the Swollen Jaw Spider, Oedignatha scrobiculata. 

Among Mygalomorph Spiders, only a single genus is known to ever enter marine environments, the Intertidal Trapdoor Spiders, Idioctis spp., which construct burrows beneath the marine high tide line. These burrows are lined with a silk which apparently provides a reliable barrier against salt water, preventing the sea from entering the burrow when the tide is high. Members of this genus are known from island environments scattered across the Indian and Pacific oceans, apparently indicating an ability to occasionally disperse across wide areas of open ocean, although individual species tend to be restricted to single islands, or sometimes very close groups of islands, suggesting that such dispersals are rare.

In a paper published in the Journal of Arachnology on 6 October 2023, Kuang-Ping Yu of the Evolutionary Zoology Laboratory at the Slovenian National Institute of Biology, and the Department of Biology at the University of Ljubljana, Ying-Yuan Lo at the Department of Life Science at the National Taiwan Normal University, and the Zoology Division at the Taiwan Endemic Species Research Institute, Ren-Chung Cheng of the Department of Life Sciences and Research Center for Global Change Biology at the National Chung Hsing University, Robert Raven of the Biodiversity and Geosciences Program at Queensland Museum, and Matjaž Kuntner, also of the Evolutionary Zoology Laboratory at the Slovenian National Institute of Biology, and of the Jovan Hadži Institute of Biology, the Department of Entomology at the Smithsonian National Museum of Natural History, and the State Key Laboratory of Biocatalysis and Enzyme Engineering and Centre for Behavioural Ecology and Evolution at Hubei University, describe a new species of Indertidal Trapdoor Spider from Taiwan.

The new species is named Idioctis parilarilao, where 'parilarilao' refers to both the name of the southernmost tip of Taiwan in the Paiwan language of the island, as well as to the indigenous people of the area. Specimens were discovered living both in Pingtung County on the southern tip of the Taiwanese mainland, and on Green Island, which lies off the east coast of that mainland. Female specimens ranged from 9.1 mm to 12.7 mm in length, the males were not observed. All specimens were light brown in colour, with a covering of thin, greyish hairs.

Idioctis parilarilao. (A)–(H) Female holotype (voucher code ASIZCH000106): (A) Dorsal view. (B) Lateral view. (C) Sternum and chelicera, ventral view. (D) Chelicera, ventral view showing the rastellum. (E) Eye mound, dorsal view. (F) Chelicera, ventral view showing the promarginal and basomesal teeth. (G) Spinnerets, ventral view. (H) Vulva, dorsal view. (I) Vulva of female paratype (ASIZCH000107), dorsal view. (J) Vulva of female from Green Island (TESRI-Ar5761), dorsal view. Scale bars: (A), (B) 3 mm; (C), (D), (G) 1 mm; (E), (F), (H), (I), (J) 0.5 mm. Yu et al. (2023).

Idioctis parilarilao was observed inhabiting tubular burrows dug into Coral rocks or cliffs within the intertidal zone, emerging at night when the tide was low to ambush small Arthropods. The trapdoors were covered by a camouflage incorporating Coral sand, debris, and Algae. The burrows were connected to natural chambers within the rock, which served as reserves of air at low tide. Breeding behaviour of the species is unclear, but large numbers of spiderlings were seen on rocks above the tideline in October.

Nest of Idioctis parilarilao sand its surrounding environment. Yu et al. (2023).

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Typhoon Doksuri makes landfall in China, after leaving at least 39 people dead in the Philippines.

Typhoon Doksuri made landfall in Fujian Province, China, on the morning of Friday 28 July 2023, after claiming at least 39 lives as it passed across the Philippines earlier this week. The dead in the Philippines include a mother, her child, and two other children that were in the same house when it was buried by a landslide at Baguis in Benguet Province, on Wednesday 26 July. Landslides are a common problem after severe weather events, 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. These combined often lead to catastrophic flooding in areas hit by tropical storms.. Also in Benguit Province a 17-year-old was killed in a lamdslip triggered by heavy rains. In Isabela Province, a woman selling bread from a bicycle cart was killed by a falling tree. The majority of those who lost their lives, however, were on a ferry travelling town of Binangonan on Luzon Island and the smaller island of Talim, which capsized about 50 m after setting sail. Thirty people have now been confirmed dead following this incident, with many more still missing.

The MV Princess Aya, which capsized shortly after leaving the port of Binangonan on Luzon Island on Thursday 27 July 2023. The vessel overturned after encountering strong winds associated with Typhoon Doksuri, killing at least 30 passengers. The ferry is believed to have had about 70 people onboard when it sank, despite being licenced for only 40. The captain and engineer of the vessel have been arrested and may face charges. Rappler.

After passing over the Philippines Typhoon Doksuri swept to the south of Taiwan, brining with it winds gusting at up to 191 km per hour, and rains of up to 70 mm. Around 4000 people were evacuated from vulnerable areas as a precaution, and all internal and most international flights were grounded as a precaution. In the event there have been no major damage or casualties reported, although about 15 700 houssholds temporarily lost their power. In Fujian Province around 400 000 people were evacuated from areas deemed at risk, all boats were required to return to port as a precaution, and almost all transport services were suspended. No casualties have been reported in Fujian, and the only significant damage was to a sports stadium, which lost part of its roof.

Waves associated with Typhoon Doksuri battering the coast of Fujian Province, China, on Thursday 27 July 2023. Wei Peiquan/Xinhau/AP.

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 formation of a tropical cyclone. Natural Disaster Management.

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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Magnitude 6.8 Earthquake in Taiwan kills at least one.

The Taiwan Central Weather Bureau reported a Magnitude 6.8 Earthquake at a depth of 7.0 km in Taitung County, Taiwan, slightly before 2.45 pm local time (slightly before 7.45 am GMT) on Sunday 18 September 2022. The event is reported to have killed at least one person, with several more injured, and to have caused the collapse of a three story building in Hualien and a bridge in Yuli, as well as damage to numerous other structures.

Rescue workers pulling a five-year-old girl from a collapsed building in Hualien City, Taiwan, following a Magnitude 6.8 Earthquake on Sunday 18 September 2022. AP.

Taiwan has a complex tectonic setting, lying on the boundary between the Eurasian and Philippine Plates, with the Eurasian Plate being subducted beneath the Philippine Plate in the South and the Philippine Plate being subducted beneath the Eurasian in the East. Subduction is not a smooth process even in simple settings, with plates typically sticking together as pressure from tectonic expansion elsewhere builds up, then suddenly breaking apart and shifting abruptly, causing Earthquakes.

The motion of the tectonic plates beneath Taiwan. The University of Memphis.

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