Wednesday, 27 January 2021

Eruptions and pyroclastic flows on Mount Merapi.

Mount Merapi, a 2970 m stratovolcano (cone-shaped volcano made up of layers of ash and lava) in Central Java, considered to be one of Indonesia's most active, erupted on Wednesday 27 January 2021, producing a column of ash 3000 m high away, as well as several new lava streams and pyroclastic flows (avalanches of hot ash and gas). There are no reports of any casualties associated with this eruption, and nor would they be expected, as a 3 km exclusion zone has been in place around the volcano since the current eruption cycle began in November 2020, although a number of elderly people have been evacuated from nearby communities by the Badan Nasional Penanggulangan Bencana.

 
A pyroclastic flow on Mount Merapi on 27 January 2021. Agung Supriyanto/AFP.

 
The approximate location of Mount Merapi. Google Maps.

See also...














Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter

 

Magnitude 4.4 Earthquake in Granada Province, Spain.

The United States Geological Survey recorded a Magnitude 4.4 Earthquake at a depth of 10 km, about 3 km to the northwest of the city of Atarfe in Granada Province, Spain slightly before 10.55 pm local time (slightly before 9.55 pm GMT) on Tuesday 26 January 2021. There are no reports of any damage or injuries associated with this event, but it was felt locally.

 
The approximate location of the 26 January 2021 Granada Earthquake. USGS.

The quake is likely to be related to Spain's location on the Iberian Peninsula and the natural tectonic stresses encountered there. Iberia is located on the extreme southwest of the Eurasian Plate, close to the margin with Africa, which is pushing into Europe from the south. At the same time there is a lesser area of geological expansion beneath the Bay of Biscay, pushing Iberia southwards. This leads to considerable tectonic stress in southern Spain, leading in turn to the occasional Earthquake.

See also...














Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter.


Tuesday, 26 January 2021

Citizen scientist network records a decline in Whale Shark deaths along the Venezuelan Caribbean coast.

At the beginning of this century, observations of the Endangered Whale Shark, Rhincodon typus, in Venezuelan waters comprised 20 opportunistic records spanning the previous 51 years, suggesting they were present infrequently. A decade later, there were sightings year-round, distributed all along the coast. News of killings of whale sharks also became more frequent. In 2014, the Centro para la Investigación de Tiburones de Venezuela began to systematically document Whale Shark observations and engage fishers linked to Shark encounters. They interviewed 222 people from 17 towns, spanning Maracaibo in the west to Margarita Island in the east. Reports included 142 sightings and 21 deaths of Whale Sharks during 2014-2017, the latter by entanglement in nets, harpooning or other capture methods. Although most encounters were opportunistic or incidental, they generally lead to the killing of Sharks and the sale of their fins.

 
A Whale Shark, Rhincodon typus, off the coast of Venezuela. Centro de Investigación para Tiburones.

In a paper published in the journal Orynx on 21 September 2020, Leonardo Sánchez, Yurasi Briceño, and Rafael Tavares of the Centro de Ecología at the Instituto Venezolano de Investigaciones Científicas, and the Centro para la Investigación de Tiburones de Venezuela, Dení Ramírez-Macías of Tiburón Ballena México, and Jon Paul Rodríguez, also of the Centro de Ecología at the Instituto Venezolano de Investigaciones, present the results of these documenting activities.

In 2016-2020 the organization visited the 17 coastal towns where reports were more frequent. Firstly, they contacted community leaders and fishers connected to Shark kills, built personal relationships, developed trust, and explained the work of the organisation. After one or two visits, workshops at schools, fisher cooperatives or local businesses expanded the visibility of and interest in the project. An invitation to share information on social media followed. Whale Shark sightings now reach the organisation within minutes. Fishers film untangling and releasing of Sharks instead of killing them. Others film themselves swimming with Whale Sharks. Diving operators offer Whale Shark watching tours, increasing their value from a one-time sale of fins to repeat visits with tourists.

The clearest success indicator, however, is a sharp decline in Shark killing. Prior to October 2017, interviews documented 21 Shark kills. In contrast, during 2018-2020, after implementation of workshops, relationship building, and establishment of the social media network, no Whale Shark killings were reported. Although underreporting is possible, it seems likely that the news would reach the organisation, in particular as news of captures of other Shark species rapidly spread. The evidence collected through this citizen scientist network suggests that the Whale Sharks seen are mostly juveniles
(with a mean length of about 7 m), and appear in a number of localities along the Venezuelan coast. Reports have mentioned the presence of 1-10 Sharks simultaneously and during several months. Additional field data would facilitate estimation of seasonality and abundance. Although past records suggest Whale Sharks were only present occasionally along the Venezuelan coast, they are now a common occurrence and perhaps are here to stay.

See also...














Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter


Woman dies after being trampled by Elephant at tourist resourt in Kerala State, India.

A woman has died after being trampled by an Elephant at a resort in the Wayanad District of Kerala State, India, on Saturday 23 January 2021. The victim, described as Shahana Sathar, the head of the psychology department at the Darunnujoom College of Arts and Science, was staying in a tent at a campsite on the resort with her cousin and a friend; she was reportedly attacked by a wild Elephant while sitting near the tent, and died of crush injuries to the chest at the scene of the incident. The resort has now been closed by Forest Department officials, who had previously warned the owner about the dangers of locating campsites too close to the forest edge, and who are now planning legal action. The campsite is described as being located on a landslide-prone slope, surrounded by dense forest, with no protection from animals. Local environmental group Wayanad Prakruti Samrakshana Samiti has warned about the large number of such camps that have sprung up in the region, with about 300 ventures operating campsites and tree huts in the forests, with no official permission and little regard for the safety of guests or the environment.

 
A campsite at the Rainforest Resort in the Wayanad District of Kerala State, India, where a woman was killed by an Elephant on 23 January 2021. India Today.

The population of India has risen from 376 million in 1950 to 1339 million today, fuelling an expansion of both urban and agricultural land use into former wilderness areas. The wild Elephant population has declined over the same period, but still stands at about 27 000. Many animals will simply flee such incursions, or, if unable to, are likely to end up in the cooking pots of hungry villagers. Elephants, however, are a somewhat different proposition. They are large animals, not used to being challenged by other animals in their home ranges, and typically live in matriarchal herds of up to a hundred, with herds holding large territories, criss-crossed by Elephant trails. A herd of Elephants encountering a new Human settlement, particularly a poorly defended structure, are unlikely to attempt to go round it, and are quite likely to maximise the damage they cause to show their displeasure. This has resulted in an increasing cycle of Elephant-Human conflict in rural areas of India, with 2361 people killed by Elephants between 2014 and 2019, while in the same period 510 Elephants were killed by people.

See also...














Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter.

 

Asteroid 2021 BO1 passes the Earth.

Asteroid 2021 BO1 passed by the Earth at a distance of about 251 000 km (0.65 times the average distance between the Earth and the Moon, or 0.17% of the distance between the Earth and the Sun), slightly after 2.15 am GMT on Wednesday 20 January 2021. There was no danger of the asteroid hitting us, though were it to do so it would not have presented a significant threat. 2021 BO1 has an estimated equivalent diameter of 3-9 m (i.e. it is estimated that a spherical object with the same volume would be 3.-9 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 32 km above the ground, with only fragmentary material reaching the Earth's surface.

 
The closest approach of 2021 BO1 to the Earth on 20 January 2021. JPL Small Body Database.

2021 BO1 was discovered on 18 January 2021 (two days before its closest approach to the Earth) by the University of Arizona's Mt. Lemmon Survey at the Steward Observatory on Mount Lemmon in the Catalina Mountains north of Tucson. The designation 2021 BO1 implies it was the 39th asteroid (asteroid O1; 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 = 26, A2 = 51, etc., which means that O1 = (25 x 1) + 14 = 39) discovered in the second half of January 2021 (period 2021 B; the year being split into 24 half-months represented by the letters A-Y, with I being excluded).

 
The orbit and current position of 2021 BO1. The Sky Live 3D Solar System Simulator.

2021 BO1 has a 1144 day (3.13 year) orbital period, with an elliptical orbit tilted at an angle of 0.12° to the plain of the Solar System which takes in to 0.92 AU from the Sun (92% of the distance at which the Earth orbits the Sun) and out to 3.36 AU (336% of the distance at which the Earth orbits the Sun, and more than twice the distance at which the planet Mars orbits the Sun). It is therefore classed as an Apollo Group Asteroid (an asteroid that is on average further from the Sun than the Earth, but which does get closer). This means that Asteroid 2020 YN2 has occasional close encounters with the Earth, with the next predicted for May 2024.

See also...














Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter.