At least 26 dead in flooding and landslides in the Vale do Aço metropolitan area of Minas Gerais State, Brazil.

At least 26 people have died, and several more are missing, after a series of floods and landslide events hit the Vale do Aço metropolitan area of Minas Gerais State, Brazil, on Sunday 12 and Monday 13 January 2025. Nine of the fatalies, including a nine-year-old boy, occurred when a landslide in the Betânia neighbourhood of the city of Ipatinga, where a landslide swept along a steeply inclined street, destroying a number of homes. Other fatalities, including in at least two further children, were caused by landslides in the Betânia, Canaã, and Vila Celeste neighbourhoods of the city, and another in the city of Santana do Paraíso, to the north of Ipatinga. The events followed several days of heavy precipitation in the area, with 326 mm of rain falling between Saturday 11 and Monday 13 January, including 80 mm in an hour on Saturday night. 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.

A rescue worker searching through debris following a landslide in the city of Ipatinga. Minas Gerais Fire Department. 

Southern Brazil has a rainy season that lasts from October to March, with peak rains from mid-November to mid-January, however, this year's rains have been exceptionally strong. Brazil has suffered a string of flood-related disasters in recent years, most notably in 2011, when over 800 people died. The country has a rapidly growing population, with little effective urban planning, which has led to sprawling urban developments springing up with little thought to natural hazards, and in particular poorer neighbourhoods often expanding up unstable hillsides, with the result that when floods occur (which is not unusual) communities are often quickly overwhelmed.

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Fireball meteor over southern Brazil.

Witnesses in Bahia, Distrito Federal, Espírito Santo, Goiás, Mato Grosso do Sul, Minas Gerais, Paraná, Rio de Janeiro and São Paulo states have reported observing a bright fireball meteor slightly before 6.40 pm local time (slightly before 9.40 pm GMT) on Monday 19 June 2023 (slightly before 6.00 am on Sunday 7 June, GMT). The fireball is described as having moved from northeast to southwest, entering the atmosphere over Minas Gerais State and disappearing over São Paulo. A fireball is defined as a meteor (shooting star) brighter than the planet Venus. These are typically caused by pieces of rock burning up in the atmosphere, but can be the result of man-made space-junk burning up on re-entry.  

The 19 June 2023 Brazilian fireball seen from Passos in Minas Gerais State. Denilson Silva/American Meteor Society.

Objects of this size probably enter the Earth's atmosphere several times a year, though unless they do so over populated areas they are unlikely to be noticed. They are officially described as fireballs if they produce a light brighter than the planet Venus. The brightness of a meteor is caused by friction with the Earth's atmosphere, which is typically far greater than that caused by simple falling, due to the initial trajectory of the object. Such objects typically eventually explode in an airburst called by the friction, causing them to vanish as an luminous object. However, this is not the end of the story as such explosions result in the production of a number of smaller objects, which fall to the ground under the influence of gravity (which does not cause the luminescence associated with friction-induced heating).

Heat map showing areas where sightings of the meteor were reported (warmer colours indicate more sightings), and the apparent path of the object (blue arrow). American Meteor Society.

These 'dark objects' do not continue along the path of the original bolide, but neither do they fall directly to the ground, but rather follow a course determined by the atmospheric currents (winds) through which the objects pass. Scientists are able to calculate potential trajectories for hypothetical dark objects derived from meteors using data from weather monitoring services.

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Landslides and flash floods kill at least fifty four in Brazil.

A series of landslides and flash floods have killed at least fifty four people in Brazil since Thursday 23 January 2020. As well as the known deaths a further eighteen people are currently missing, and over 30 000 people have been forced to flee their homes in the states of Minas Gerias, Espirito Santo, and Rio Grande do Sul. The rains began on Thursday 23 January, when over 100 mm of rain fell in twenty four hours in parts of Minas Gerias, the most rain recorded in a single day for over a century, and are predicted to continue for at least the rest of this week. 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.

 Rescue workers search the site of a landslide in the Vila Ideal neighborhood in Belo Horizonte, Minas Gerais State, Brazil, on Friday 24 January 2020. Cristiane Mattos/Reuters.

 Southern Brazil has a rainy season that lasts from Ocotober to March, with peak rains from mid-November to mid-January, however, this year's rains have been exceptionally strong. Brazil has suffered a string of flood-related disasters in recent years, most notably in 2011, when over 800 people died. The country has a rapidly growing population, with little effective urban planning, which has led to sprawling urban developments springing up with little thought to natural hazards, and in particular poorer neighborhoods often expanding up unstable hillsides, with the result that when floods occur (which is not unusual) communities are often quickly overwhelmed. This years exceptional rains have led to more widespread flooding, which may also persist for longer, and there is a distinct danger that without determined action the death toll may exceed that of 2011.

Flooding in Belo Horizonte on 24 January 2020. TV Brasil.

This extreme weather may be linked to a developing El Niño wearther system over the Pacific Ocean. The El Niño is the warm phase of a long-term climatic oscillation affecting the southern Pacific, which can influence the climate around the world. The onset of El Niño conditions is marked by a sharp rise in temperature and pressure over the southern Indian Ocean, which then moves eastward over the southern Pacific. This pulls rainfall with it, leading to higher rainfall over the Pacific and lower rainfall over South Asia. This reduced rainfall during the already hot and dry summer leads to soaring temperatures in southern Asia, followed by a rise in rainfall that often causes flooding in the Americas and sometimes Africa. Worryingly climatic predictions for the next century suggest that global warming could lead to more frequent and severe El Niño conditions, extreme weather conditions a common occurrence.

Movements of air masses and changes in precipitation in an El Niño weather system. Fiona Martin/NOAA.

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Redudasys brasiliensis: A new species of Redudasyid Gastrotrich from Brazil.

Gastrotrichs are a phylum of minute animals, generally less than a millimetre in length, found in interstitial spaces in sediments (a phylum is the highest classification of organisms below that of kingdom; other animal phyla include Molluscs and Arthropods, the Vertebrates only have the status of a subphylum within the Phylum Chordata, which also includes animals such as Sea Squirts and Lancets). Their small size meant that they went unnoticed until the event of microscopy, with the group not being discovered until the 1860s. These animals appear to be almost ubiquitous in marine and freshwater ecosystems, as well as semi-terrestrial ecosystems such as bogs and swamps, although the majority of non-marine species belong to one of the two orders of Gastrotrichs, the bottle-shaped Chaetonotida, with the other order, the worm-like Macrodasyida, far less common, and all coming from a single family, the Redudasyidae.

In a paper published in the journal Scientific Reports on 14 February 2019, André Garraffoni of the Department of Animal Biology at the State University of Campinas, Thiago Araújo of the Departament of Zoology at the Federal University of Minas Gerais, Anete Lourenço of the Department of Biological Science at the Federal University of Jequitinhonha and Mucuri Valleys, and Loretta Guidi and Maria Balsamo, of the Department of Biomolecular Sciences at the University of Urbino, describe a new species of Gastrotrich from Minas Gerais State, Brazil.

The new species is placed in the genus Redudasys and given the specific name brasiliensis, meaning 'from Brazil'. These Gastrotrichs are 302–376 μm in total body length, with a body separated into head, trunk and caudal (tail) regions. The head is rounded with several sensory cilia, but lacking tentacles or ocelli (simple eyes). The trunk is cylindrical, two-lobed at the posterior, and lacks a peduncle (narrow region to which the tail is connected). The body is covered by a smooth cuticle without ornamentation, and there are paired bristles along the sides. There are adhesive tubes at the front and rear of the animal.

Redudasys brasiliensis, Scanning electron micrograph in dorsolateral view and close-up of an anterior adhesive tube (inset). c, locomotory ventral ciliation; e, egg; m, mouth; ph, pharynx; sb, sensory bristles; TbA, anterior adhesive tubes; TbP, posterior adhesive tubes. Garraffoni et al. (2019).

Redudasys brasiliensis was found in sediments of the Jequitinhonha Drainage Basin, where it is relatively common, and sediments of the São Francisco Drainage Basin, where it was more rare. It's distribution beyond this is unknown. The locations where it was found were all above 900 m above sealevel, in rocky areas with a highly endemic (localised) vegetation.

Redudasys brasiliensis. Reconstruction of the musculature from confocal laser scanning microscopy images. (a) Schematic drawing of musculature in dorsal view. (b) Schematic detail of ventral musculature in the pharyngeal and the caudal regions. (c) Volocity-rendered 3D view of muscles in lateral view. Confocal micrographs of phalloidin-stained specimens. (d) Helicoidal muscles in the pharynx (arrow). (e) Detail of the pharynx posterior end with pharyngeal pores. asm, anterior semicircular muscle; cm, circular muscles; dlm, dorsal longitudinal muscles; llm, dorsal longitudinal muscles; mr,  mouth ring, plm, pharyngeal longitudinal muscles; pp, pharyngeal pore; psm, posterior semicircular muscle; vlm, ventrolateral muscles. Garraffoni et al. (2019).

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Hundreds feared dead after collapse of mine tailings dam in Minas Gerais State, Brazil.

Ten people have now been confirmed dead and over 200 more are missing, following the collapse of a tailings dam at a Vale mining operated iron mine in Minas Gerais State, Brazil, on Friday 25 January 2019. The incident happened close to the Alegria Mine site where a similar tailings dam collapse in November 2015, resulting in 19 deaths and a major environmental catastrophe which is still causing problems today. The dam that collapsed this week is only about a fifth of the size of that dam, and is not thought likely to cause environmental problems on the same scale, but it is feared that the number of deaths will be much greater, as the dam was uphill of an encampment used by workers at the mine.

The remains of a mine camp in Minas Gerais State, Brazil, where it is feared over 200 people died when the camp was hit by a wave of slurry following the collapse of a tailings dam on 25 January 2019. Leo Drumond/Nitro/AP.

Tailings ponds are used to store sediment-laden waters from mines; such waters typically contain a high proportion of fine silt and clay particles, which take time to settle out of the water. The resulting water may be fairly clean, or may contain other pollutants (typically acids, either generated by the local geology or used in the mining process), and need further treatment. In some instances acid is added to such pools in order to dissolve the product, which is then released from the resultant chemical slurry by further treatment, however this is not a typical procedure at iron ore mines.

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Brazilian municipality troubled by 'rain' of Spiders.

The rural municipality of Espírito Santo do Dourado in Minas Gerais State, Brazil, has been troubled by a 'rain' of Spiders this week; a phenomenon in which thousands of Spiders build webs strung from tree-to-tree (or where the opportunity arises, from tree-to-telegraph-pole-to-house-to-tree), high above the town, with the sky appearing filled with Spiders, a harmless, if somewhat alarming sight. This phenomenon is apparently not unusual in this time of year, when the warm, humid climate provides ample insect food for social Spiders of the species Parawixia bistriata.

 

 'Rain' of Spiders over Espírito Santo do Dourado in Minas Gerais State, Brazil, this week. João Pedro Fonseca Martinelli/Terra do Mandu.

Social Spiders are unusual in that the females form colonies of hundreds to thousands of individuals, which cooperate in the building of webs, capture of prey, defence of the colony and raising of young. Unlike in Insects, where social numerous highly successful species are known in several groups, most of which are exclusively social, of the approximately 41 000 known species of Spider only about 25 are social. However sociality appears to have arisen separately at least 18 times in tropical and subtropical Spiders, suggesting that under some circumstances there must be strong evolutionary pressure for Spiders to develop sociality.

Of the 28 described species of Parawixia, only Parawixia bistriata is social, with females resting in a communal nest during the hottest part of the day, and building a framework of long web strands between trees and other tall structures, with individual Spiders building their own orb-webs (which are defended assertively against intrusion by other Spiders) on this framework.

Typical behaviours of Parawixia bistriata. (a) The Spiders’ daytime retreat or bivouac (white arrow). (b) Spiders leaving the bivouac en masse after sunset. (c) Two Spiders passing each other, without any aggressive interaction, while depositing silk on the main support lines before initiating web building. (d) A Spider that has just completed her web. (e) A webless spider (top) is being bounced at by a web owner (bottom). (f) A prey item is shared between a web owner, a spider from a neighbouring web, and a webless spider that had been at the edge of the web. Wenseleers et al. (2013).

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Difroehlichia elenae: A new species of Terrestrial Flatworm from Minas Gerais State, Brazil.

New World Terrestrial Flatworms, Geoplanidae, are carnivorous free-living Platyhelminth Worms found in terrestrial habitats. Like other Platyhelminths they have a very simple bodyplan, lacking an internal body cavity which holds the organs or any form of circulatory system or reproductive organs. They have flattened bodies, which allows oxygen absorbed through the skin to reach all the cells, with a simple gut with a single opening that serves as both the mouth and anus. Most Land Flatworms are extremely limited in their environmental tolerances, and consequently have very limited geographical ranges, but a few species have proved to be much more tolerant and have become highly invasive pest species.

In a paper published in the journal PeerJ on 4 December 2018, Ana Leal-Zanchet and Alessandro Damasceno Marques of the Instituto de Pesquisas de Planárias at the Universidade do Vale do Rio dos Sinos, describe a new species of Terrestrial Flatworm from Minas Gerais State in Brazil.

The new species is described from a single specimen assessed to be a member of the New World Terrestrial Flatworm Family Geoplaninae, on the basis of its subcylindrical body, poorly developed sub-epidermal musculature and a narrow creeping sole. However, it could not be assigned to any previously described genus within that family, and is therefore placed in a new genus, named Difroehlichia, in honour of Claudio Froehlich and the late Eudóxia Froehlich, for their work on the study of terrestrial Flatworms, and given the specific name elenae, in honour of the late Elena Diehl, for her studies of the Ants and Termites of southern Brazil.

Difroehlichia elenae is dark brown in colour and has a length of 13.5 mm and width of 1.5 mm. It has eyes along the margins of both sides of its body, with the exception of the very tip; these are small and monolobate towards the front of the animal and larger and trilobate along the majority of the body, becoming sparse towards the rear. The body is divided into two parts by a muscular, cylindrical pharynx, which is where the mouth is located.

Difroehlichia elenae, general dorsal view of preserved specimen. The arrow indicates the anterior extremity. Leal-Zanchet & Marques (2018). 

The specimen was found in the entrance to a cave in banded ironstone in an area of cerrado grassland, with a laterite soil and numerous rocky outcrops at the eastern margin of the Serra do Espinhaço Plateau, during the rainy season (November). It appeared to have recently mated and produced eggs, and it is possible that it had come to the cave for this purpose.

Entrance of the ferruginous cave at the basis of a vertical slope in rocky outcrop in the Brazilian where Difroehlichia elenae was discovered. Leal-Zanchet & Marques (2018).

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