Homes evacuated after landslide in the Shandon District of Cork, Ireland.

Several homes were evacuated following a landslide on Eason's Hill in the Shandon District on the north-side of the City of Cork in Ireland on Thursday 20 February 2020. The landslip caused gardens behind the properties to vanish, and while the residents of the properties have now been allowed to return to them, they are now extremely concerned about the future safety of living in the area. The incident happened amid heavy rainfall associated with Storm Denis. 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. 

 Properties undermined by a landslide on Eason's Hill in the Shandon District of Cork, Ireland, on Thursday 20 February 2020. Irish Examiner.

Residents of the area have asked the local council for help protecting their properties, however this request has been rejected so far on the basis that the landslip was triggered by the failure of a retaining wall (a structure designed to restrain soil to a slope that it would not naturally keep to), which was itself located on private land, making the issue one that should be settled between the landowners involved.

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Fireball meteor over southern Ireland.

Witnesses across Britain and Ireland have reported witnessing a fireball meteor slightly before 8.00 pm local time (slightly  before 7.00 pm GMT) on Monday 28 October 2019. The majority of sightings came from Ireland, but with many sightings In Wales, Scotland and northern England. 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. On this occasion many reports stated that the meteor was green, suggesting that the meteor had a high magnesium or nickel content, and moving southeast to northwest, first entering the atmosphere over the Celtic Sea and disappearing somewhere over County Cork.

Fireball meteor seen from outside Banteer in County Cork on 28 October 2019. Sean Linehan/Irish Independent.

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).

 

 Map showing areas where sightings of the meteor were reported, 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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People warned to keep away from a sinkhole on the Beara Peninsula in County Cork, Ireland,

Cork County Council has issued a warning to people to keep away from a sinkhole that appeared on the  L-8912-0 road to the south of the village of Allihies on the Beara Peninsula in the west of the county over the weekend. The sinkhole is about six metres in diameter, and it is unclear if it is likely to grow further, which has prompted the council to close the road, which is described by locals as 'quite busy'.

Sinkhole on the Beara Peninsula in County Cork that opened up this weekend. Teddy Kelly/Irish Independent.

Sinkholes are generally caused by water eroding soft limestone or unconsolidated deposits from beneath, causing a hole that works its way upwards and eventually opening spectacularly at the surface. Where there are unconsolidated deposits at the surface they can infill from the sides, apparently swallowing objects at the surface, including people, without trace.

The approximate location of the October 2019 Beara Peninsula sinkhole. Google Maps.

On this occasion the sinkhole is thought likely to have been caused by the collapse of a shaft at a former copper mine in the area. The Allihies Copper Mine operated from the early nineteenth century until the late 1950s,  at its peak employing around 1600 people. It is possible that part of the mine has collapsed due to recent wet weather in the area, and Cork County Council has asked the Exploration and Mining Division of the Department of Communications, Climate Action and Environment to carry out a survey of the site. The council is also trying to ascertain who now owns the former mine.

Remaining surface structures at the Allihies Copper Mine. Allihies Copper Mine Museum.

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Warning issued to bathers after large number of Portuguese Man 'o War found on beach in County Cork, Ireland.

A warning has been issued to bathers after a large number of Portuguese Man 'o War, Physalia physalis, were found washed up on Ballydonegan Beach in County Cork, Ireland, on Saturday 28 September 2019. People are being urged to be wary of both the animals themselves, and any detached tentacles, as the venom of the species is particularly potent, and can occasionally kill Humans, though children and pets are thought to be more at risk than adults.

A group of Portuguese Man 'o War on Ballydonegan Beach in County Cork, Ireland, on Saturday 28 September 2019. Sue Swansborough/Cork Beo.

Portuguese Man o' War are colonial Siphonophores only distantly related to true Jellyfish, Scyphozoa, though commonly referred to as such. Their bodies are made up of thousands of individual zooids, each with their own sting, tentacles and digestive system. New zooids are formed by budding from other members of the colony, but remain attached to these to form a single colony. Each year a generation of specialist sexual zooids (gonozoids) is produced which produce eggs and sperm, with fertilised eggs going on to form new colonies. These animals are anchored to the sea surface by a highly modified zooid which forms an air sack, filled with a mixture of carbon monoxide defused from the zooid and nitrogen, oxygen and argon from the atmosphere, which are brought into the sack through osmosis.

Portuguese Man o' War produce an extremely strong venom, for both capturing food and defending the colony, and which is capable of causing extremely painful stings, and sometimes death, in Humans, for which reason people are advised to be extremely cautious on beaches where these animals wash up, not just of entire animals but also detached tentacles, which are less visible but still capable of stinging.

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