Showing posts with label Colombia. Show all posts
Showing posts with label Colombia. Show all posts

Saturday, 28 February 2026

Mud volcano reported to have killed several Cattle near the town of San Juan de Urabá in Colombia.

A number of Cattle are reported to have died following a mud volcano eruption near the town of San Juan de Urabá in Antioquia Department on the Caribbean coast of Colombia on 25 February 2026. The volcano erupted at about 6.20 pm local time, producing a large column of fire as ejected gas ignited, setting fire to vegetation and damaging the road between San Juan de Urabá and San Juancito, which drivers are advised to avoid until repairs are carried out and an assessment of potential future hazards is carried out.

A gas explosion caused by a mud volcano near the town of San Juan de Urabá in Colombia on 25 May 2026. Unidad Nacional para la Gestión del Riesgo de Desastrest.

Unlike regular volcanoes, mud volcanoes are not caused by magma erupting from within the Earth's interior, but rather gasses escaping from buried sediments closer to the surface. Typically this is methane generated by the decomposition of buried vegetation in areas where sediments are accumulating rapidly, leading to the decaying material becoming pressurised. Under these circumstances, the compressed gas will force its way through any cracks into softer layers above (the mud), then erupt rapidly, often bringing lighter oil fractions, also produced by the decomposition of plant material, with it. This creates an explosive mixture, which often ignites in the way seen in Colombia this week, although on other occasions more liquid mud than flammable gas is ejected, creating a messier, but less dramatic eruption.

The site of the mud volcano eruption the following day. The road between San Juan de Urabá and San Juancito can be seen to the left. Gobernación de Antioquia.

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Thursday, 18 January 2024

Thirty seven known deaths following landslide in Chocó Department, Colombia.

Thirty seven people have now been confirmed dead, nineteen have been treated for a variety of injuries, and many more are thought to be buried under debris, following a landslide near the community of Carmen de Atrato in Chocó Department, Colombia, on Friday 12 January 2024. The landslide hit a section of road close to another section of road which had been closed due to an earlier landslide. About 60 people were waiting here in the hope that the road would be re-opened when the landslide hit. A large number of women and children from the group were waiting in a house where the owners had offered them food and shelter from the rains, but which was caught at the centre of the landslide.

Rescue workers searching for bodies buried beneath mud following a landslide in Chocó Department, Colombia, on 12 January 2024. Getty Images.

The landslides happened amid heavy rains in the area, following a period of drought. 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. January is one of the drier months in Chocó Department, which has a tropical climate and is largely covered by rain forests, although the average rainfall for the month is still about 400 mm. 

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Sunday, 20 August 2023

Magnitude 6.1 Earthquake in Colombia results in at least one death.

The Colombian National Geological Service recorded a Magnitude 6.1 Earthquake at a depth of 30.0 km, beneath the town of El Calvario in Meta Department, about 90 km to the northeast of Bogatá, slightly before 12.05 pm local time on Thursday 27 August 2023 (slightly after 5.05 pm GMT). There are no reports of any damage associated with this event, though a woman is reported to have died while trying to evacuate a 10 story building in Bogatá.

The approximate location of the 17 August 2023 Colombia Earthquake. USGS.

Colombia is on the west coast of South America and the western margin of the South American Plate, close to where the Nazca Plate, which underlies part of the east Pacific, is being subducted along the Peru-Chile Trench. The Nazca Plate passes under the South American Plate as it sinks into the Earth, this is not a smooth process and the plates repeatedly stick together then break apart as the pressure builds up, causing Earthquakes. As the Nazca Plate sinks further it is partially melted by the friction and the heat of the Earth's interior. Some of this melted material then rises through the overlying South American Plate, fuelling the volcanoes of Colombia and neighbouring countries.

The subduction of the Nazca Plate beneath the South American Plate, and how it causes Earthquakes and volcanoes. SIO SEARCH.

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Saturday, 8 July 2023

Leopardus narinensis: A new species of Tigrina Cat from Nariño Department in southern Colombia.

A large number of new species of Mammals have been proposed from the Neotropical Region in recent years, including new species of Capuchin, Marmoset, Deer, Coati, Peccary, River Dolphin, Tapir, Sloth, Olingo, Bat, Rodent, and Anteater. Not all of these new species are universally accepted, with doubts cast on whether some proposed new species have been shown to be genuinely genetically and ecologically isolated from their closest relatives, although the majority have gained wide acceptance.

There are currently eleven species of Felid known from Central and South America, eight of which are placed in the Genus Leopardus, including the Ocelot, Leopardus pardalis, the Margay, Leopardus wiedii, the Andean Cat, Leopardus jacobita, the Pampas or Colocolo Cat, Leopardus colocola, the Kodkod, Leopardus guigna, Geoffroy's Cat, Leopardus geoffroyi, the Oncilla or Tigrina, Leopardus tigrinus, and the recently differentiated Southern Tigrina, Leopardus guttulus.

The taxonomy of Tigrinas has been problematic since the species was first described by Johann Christian Daniel von Schreber in 1775, as Felis tigrina. Schreber's description was based upon a specimen from Cayenne in French Guiana, of which he provided a plate with the label 'La Margay', thereby introducing confusion as to the differentiation between Margays and Tigrinas. The same species was named again in 1867 as Felis pardinoides by John Edward Gray (who had created the genus Leopardus in 1842), who give India as a type locality, later changing it to Bogata, Colombia (such errors were not uncommon for nineteenth century zoologists working with museum specimens, which were often purchased from unreliable vendors). A variety of other Felis species were described from South America in the ensuing years, as well as several species assigned to the (now defunct) genus Margay, with it not being recognised that all these Cats were members of a single genus until the twenty first century.

The Tigrina (as either Felis tigrina or Leopardus tigrinus) has long been seen as a species including a considerable amount of diversity, with numerous proposed sub-species, four of which have persisted into recent usage, although one of these has recently been separated out as a separate species, the Southern Tigrina, Leopardus guttulus, on the basis of genetic data. Tigrinas can be divided into three distinct morphotypes. The first of these is found throughout Central America and the Andean region, and while morphologically consistent, has been shown to contain several different genetic lineages, which should probably be regarded as different sub-species or even species. The second morphotype is found in northeastern and central Brazil, and is both morphologically and genetically distinct, and has been proposed to be a separate species: Snethlage's Tigrina, Leopardus emiliae. The third morphotype is found in Brazil, Paraguay, and northeastern Argentina, and is the population separated out as the Southern Tigrina, Leopardus guttulus.

In a paper published in the journal Genes on 14 June 2023, Manuel Ruiz-García and Myreya Pinedo-Castro of the Laboratorio de Genética de Poblaciones Molecular-Biología Evolutiva at the Pontificia Universidad Javeriana, and Joseph Shostell of the Math, Science and Technology Department at the University of Minnesota Crookston, describe a new species of Tigrina from Nariño Department in southern Colombia.

The new species is described from a single preserved skin from collection of the Instituto von Humboldt, which was collected in 1989 on the Galeras Volcano in Nariño Department, southern Colombia. Importantly, this specimen was preserved by drying it in the sun rather than by tanning; the later is a more reliable method of preservation, producing supple skins which can reliably be kept for a long time without decaying, but tends to destroy DNA.

Analysis of DNA taken from this specimen showed that it was comfortably different to any described species of Leopardus, forming a sister taxa to a group that included the Central and American and Andean Tigrinas, the Kodkod, and Geoffroy's Cat.

Maximum likelihood and Bayesian inference trees of 44 Felid specimens, including 18 Tigrina-like morphotype specimens analysed for their entire mitogenomes. Six different clades include Tigrina-like specimens: Leopardus emiliae with mtDNA of Leopardus colocola braccatus; the proposed new species; Leopardus guttulus; the Central American and trans-Andean Tigrina; the Andean Tigrina; and the Andean Tigrina with mtDNA closely related to that of Margays and Ocelots. The sequences of other species of Leopardus were included. Sequences of the Domestic Cat, Felis catus, and Jaguarundi, Herpailurus yagouaroundi, two species were also included which also live in the same geographical area where the Nariño Cat was sampled. The first number at the nodes indicates bootstrap support (%) (ML tree); the second number at the nodes indicates posterior probability (BI tree). Ruiz-García et al. (2023).

The preserved skin is described as the holotype, and only known specimen of a new species, Leopardus narinensis, where 'narinensis' means 'from Nariño', referred to as the Nariño Cat. It was probably a female in life, and belongs to a general Tigrina morphotype. It has rosettes in oblique chains, yet these rosettes have fuzzy edges. The ground colouration is tawny-orange, but the dorsal crest is of a darker orange-brownish colour. The tail is relatively short and is completely ringed, bearing seven complete rings and a black tip. However, this skin also has unique, diagnostic features. Its ground coloration is more reddish than in other Tigrinas, and its head and its dorsal crest are much darker. Its coat is denser and woollier. The head is rounder and wider, and the face is flatter. The body is short and relatively more robust than in other Tigrinas. 

The Nariño Cat found at the Galeras Volcano in the Nariño Department from the southern Colombian Andes and aspect of other specimens of other Tigrinas from different regions of the Neotropics. (A)–(C) Different views of the new species Leopardus narinensis. Its morphology and its mitochondrial and nuclear microsatellite DNA do not coincide with that of any known species of the Leopardus genus in Latin America. (D) Comparison of the Nariño cat (right) with an individual of tigrina (from the Caquetá Department in Colombia) with a larger range in the northern Andes and with similar mitochondrial haplotypes to those of Margays and Ocelots (left). Central American and trans-Andean Tigrinas: (E) One of the Tgrinas sampled in Costa Rica, and (F) A Tigrina analysed from Intag (Imbabura Province, Ecuador) that had a phenotype very similar to the Costa Rican Tigrinas that were analyzed and shown in the previous photo. Both Tigrinas were molecularly confirmed as well-defined Tigrina taxa or lineages. (G) Photo of a skin of a Tigrina from Venezuela that was very similar to the holotype of Felis pardinoides emerita. (H), (I) Photos showing the holotype of Margay caucensis (type locality: Las Pavas, Cauca Department, Colombia). (J) Photo of a skin that was very similar to the holotype of Margay tigrina elenae (type locality: Santa Elena, Antioquia, Colombia). (K), (L) Photos of two Tigrinas sampled in the Azuay Province (Ecuador) where the holotype of Felis pardinoides andina (type locality: Jima, Province of Azuay in southern Ecuador) was originally discovered. Photos of Leopardus colocola from Ecuador with a differentiated morphology (plus differentiated mitochondrial DNA and nuclear microsatellite alleles) from a geographical area near where the Nariño cat was discovered: (M) Specimen of Leopardus colocola killed in San Lorenzo in the Imbabura Province, northern Ecuador, and (N) Exemplar of Leopardus colocola from Macará, southern Ecuador. The morphologies of these two specimens (M), (N) differ from that of the proposed new species, Leopardus narinensis. Ruiz-García et al. (2023).

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Sunday, 28 May 2023

Magnitude 6.5 Earthquake off the northern coast of Panama and Colombia.

The United States Geological Survey recorded a Magnitude 6.5 Earthquake at a depth of 13.0 km, off the Caribbean coasts of Panama and Colombia, about 50 km to the northeast of the border between the two countries, slightly after 10.05 pm local time on Wednesday 24 May 2023 (slightly after 3.05 am on Thursday 25 May, GMT). There are no reports of any damage or casualties associated with this event, though it was felt across much of northern Colombia, Panama and parts of Costa Rica.

The approximate location of the 24 May 2023 Pananma/Colombia Earthquake. USGS.

The event happened close to the triple junction between the Panama, Caribbean, and South American plates. All three plates are drifting to the northwest, being pushed by the expansion of the Atlantic Ocean, and to a lesser extent the eastward movement of the Nazca Plate, which is being subducted beneath the South American Plate along the west coast of South America. However, the South American Plate is moving somewhat faster than the other two plates, causing the Panama Plate to be pushed to the west, creating a transform plate margin, as the Panama Plate moves west relative to the Caribbean Plate, along the northern coast of Panama, and a subductive plate margin, as the Caribbean Plate is forced under the advancing South American Plate, along the northern coast of Colombia. 

The tectonic plates underlying Central America and the surrounding areas. Wikimedia Commons.

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Tuesday, 2 May 2023

Authorities in Colombia begin evacuation of communities around Nevado del Ruiz volcano.

Authorities in Colombia have begun to evacuate communities within 15 km of Nevado del Ruiz,  5231 m stratovolcano (cone shaped volcano made up of layers of lava and ash) in the Los Nevados National Natural Park, at the northern end of the Ruiz-Tolima Volcanic Massif. No eruption has been observed on the volcano, but a series of Earthquakes have been recorded beneath it, which can be indicative of magma moving into chambers beneath a volcano, which is a prelude to many eruptions. Nevado del Ruiz is considered particularly dangerous as in 1985 it underwent an eruption which produced 35 million tonnes of volcanic material, including 700 000 tonnes of sulphur dioxide. This in turn triggered a series of lahars that swept to the northwest through a number of local communities, killing over 23 000 people.

Cráter Arenas, Volcán Nevado del Ruíz, on 10 April 2023. Servicio Geológico Colombiano/Wikimedia Commons.

The Ruiz-Tolima Volcanic Massif runs north-to-south parallel to the Parallel to the Pacific Coast of Columbia. It is fed by the subduction of the Nazca Plate beneath the South American Plate along the Peru-Chile Tench, which runs approximately parallel to the entire western coast of South America. As the Nazca Plate it sinks into the Earth's interior it is heated by the planet's interior heat. This melts minerals within the subducting plate, some of which then rise through the overlying South American Plate as magma, fueling volcanoes in the Andes along the full extent of the South American west coast.

The subduction of the Nazca Plate beneath the South American Plate, and how it causes Earthquakes and volcanoes. SIO SEARCH.

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