A waterfall is an area where water flows over a vertical drop or a series of steep drops in the course of a stream or river. Waterfalls occur where meltwater drops over the edge of a tabular iceberg or ice shelf. Waterfalls are formed in the upper course of a river in steep mountains; because of their landscape position, many waterfalls occur over bedrock fed by little contributing area, so they may be ephemeral and flow only during rainstorms or significant snowmelt. The further downstream, the more perennial a waterfall can be. Waterfalls can have a wide range of depths; when the river courses over resistant bedrock, erosion happens and is dominated by impacts of water-borne sediment on the rock, while downstream the erosion occurs more rapidly. As the watercourse increases its velocity at the edge of the waterfall, it may pluck material from the riverbed, if the bed is fractured or otherwise more erodible. Hydraulic jets and hydraulic jumps at the toe of a falls can generate large forces to erode the bed when forces are amplified by water-borne sediment.

Horseshoe-shaped falls focus the erosion to a central point enhancing riverbed change below a waterfalls. A process known as "potholing" involves local erosion of a deep hole in bedrock due to turbulent whirlpools spinning stones around on the bed, drilling it out. Sand and stones carried by the watercourse therefore increase erosion capacity; this causes the waterfall to recede upstream. Over time, the waterfall will recede back to form a canyon or gorge downstream as it recedes upstream, it will carve deeper into the ridge above it; the rate of retreat for a waterfall can be as high as one-and-a-half metres per year. The rock stratum just below the more resistant shelf will be of a softer type, meaning that undercutting due to splashback will occur here to form a shallow cave-like formation known as a rock shelter under and behind the waterfall; the outcropping, more resistant cap rock will collapse under pressure to add blocks of rock to the base of the waterfall. These blocks of rock are broken down into smaller boulders by attrition as they collide with each other, they erode the base of the waterfall by abrasion, creating a deep plunge pool in the gorge downstream.

Streams can become wider and shallower just above waterfalls due to flowing over the rock shelf, there is a deep area just below the waterfall because of the kinetic energy of the water hitting the bottom. However, a study of waterfalls systematics reported that waterfalls can be wider or narrower above or below a falls, so anything is possible given the right geological and hydrological setting. Waterfalls form in a rocky area due to erosion. After a long period of being formed, the water falling off the ledge will retreat, causing a horizontal pit parallel to the waterfall wall; as the pit grows deeper, the waterfall collapses to be replaced by a steeply sloping stretch of river bed. In addition to gradual processes such as erosion, earth movement caused by earthquakes or landslides or volcanoes can cause a differential in land heights which interfere with the natural course of a water flow, result in waterfalls. A river sometimes flows over a large step in the rocks. Waterfalls can occur along the edge of a glacial trough, where a stream or river flowing into a glacier continues to flow into a valley after the glacier has receded or melted.

The large waterfalls in Yosemite Valley are examples of this phenomenon, referred to as a hanging valley. Another reason hanging valleys may form is where two rivers join and one is flowing faster than the other. Waterfalls can be grouped into ten broad classes based on the average volume of water present on the fall using a logarithmic scale. Class 10 waterfalls include Paulo Afonso Falls and Khone Falls. Classes of other well-known waterfalls include Kaieteur Falls. Alexander von Humboldt "Father of Modern Geography" Humboldt was marking waterfalls on maps for river navigation purposes. Oscar von Engeln Published "Geomorphology: systematic and regional", this book had a whole chapter devoted to waterfalls, is one of the earliest examples of published works on waterfalls. R. W. Young Wrote "Waterfalls: form and process" this work made waterfalls a much more serious topic for research for modern Geoscientists. Ledge waterfall: Water descends vertically over a vertical cliff, maintaining partial contact with the bedrock.

Block/Sheet: Water descends from a wide stream or river. Classical: Ledge waterfalls where fall height is nearly equal to stream width, forming a vertical square shape. Curtain: Ledge waterfalls which descend over a height larger than the width of falling water stream. Plunge: Fast-moving water descends vertically, losing complete contact with the bedrock surface; the contact is lost due to horizontal velocity of the water before it falls. It always starts from a narrow stream. Punchbowl: Water descends in a constricted form and spreads out in a wider pool. Horsetail: Descending water maintains contact with bedrock most of the time. Slide: Water glides down maintaining continuous contact. Ribbon: Water descends over a long narrow strip. Chute: A large quantity of water forced through a narrow, vertical passage. Fan: Water spreads horizontally

HMT Richard Bacon (FY3587)

HMT Richard Bacon was a British Castle class naval trawler completed in 1918. She served through both world wars under two different names and had a lengthy career as a civilian fishing trawler. For a short while, she functioned as a support vessel for a famous transatlantic flight by a group of Italian bombers, she was scrapped in 1954. Richard Bacon was one of 217 Castle class trawlers laid down for the British government in the First World War. Displacing 360 short tons standard and armed with a single 12-pounder gun, she was used for coastal anti-submarine patrols. Richard Bacon was built at Welton & Gemmell at Beverley. Upon completion on 12 March 1918, she had a crew of 12 men and served an uneventful few years on anti-submarine and coastal patrol duties. After the war, she was registered as a fishing vessel at London under registry number LO438, taking up that role on 24 August 1920. After two years under Admiralty ownership, she was sold to the Boston Deep Sea Fishing & Ice Co Ltd, Boston and her London registry was closed.

As a result of the sale, she was renamed Haganby and registered at Boston under registry number BN179 and manager Fred Parkes. In 1923, she was transferred to Fleetwood, near Blackpool, when the Boston Deep Sea Fishing & Ice moved location. In February 1925, she was sold again, this time to a French fisherman named Victor Fourny, she was renamed Professeur Bergonié, after Jean Bergonié, registered at Boulogne. After several years in France, the Boston Deep Sea Fishing repurchased her on 4 March 1930, she was renamed again, this time to the Daily Chronicle, registered at Fleetwood, she returned to the same manager as in Boston, Fred Parkes. It was during this time that she had her first unusual duty – on 5 July 1933, she was chartered by the Italian Government to support a transatlantic flight by 24 Savoia-Marchetti S.55X seaplanes. The flight was led by General Italo Balbo, covered 6,100 miles, from Orbetello to Chicago, via Iceland, in 47 hours 52 minutes, she collided with the steam trawler Jacinta at St Kilda fishing grounds on 12 August 1934.

Although the starboard side of Jacinta was damaged, the Daily Chronicle remained undamaged. On 5 November 1934, her registry at Fleetwood ended, she was sold to Thomas L Devlin & Sons of Granton, registered there, renamed Commodator. On 29 August 1939, with the Second World War imminent, Commodator was requisitioned by the Admiralty once more, converted to a minesweeping trawler, becoming HMT Commodator; the hire rate was £84.6.0d per month – £2,500. In 1943, she was sold to Mrs E D Breen of Edinburgh. In June 1945, after the end of the war in Europe, she was sold to Grimsby Merchants Amalgamated Fishing Co Ltd and gained pennant number GY57 but remained under military command. On 4 October 1945, she was returned to her owner. After the war, she stayed in Grimsby, before being sold in February 1946 to Don Trawling Co Ltd in Milford Haven. On 20 April 1946 she was in the fishing grounds off the west coast of Ireland during an 85 miles per hour gale; the gale shifted 140 short tons of coal in her bunker, forcing the ship onto her beam ends – so that the deck was near-vertical.

The crew spent five and a half hours moving the coal by hand to restore her to an keel and were forced to put into Berehaven, County Cork. In July 1948, she was renamed again, to her final name: Lynandi, she had a uneventful few years, until 1954, when she had an accident which ended her career. On 14 January 1954, she was fishing off Old Head of Kinsale under her skipper W G King when her boiler developed problems, she was forced to blowdown her boiler and as a result, lost power. The steam trawler Inverforth began to tow her back to Milford, but two days and 100 miles during heavy weather, the tow parted and two attempts to reconnect it failed, she was in danger of drifting onto 23 miles distant. The Angle lifeboat and the tug Empire Rosa launched from Pembroke Dock but were unable to reach the trawler, in the middle of 40 foot waves. Inverforth and another trawler, the Thomas Booth stayed close and allowed Lynandi to keep her bearings; the storm abated through the morning, by 11 am the Empire Rosa had returned and was able to connect a tow line.

By 4:15 pm, the Lynandi was safely back in Milford harbour. Her skipper commended the actions of both his own crew and those crews who assisted, praised the seaworthiness of his ship, saying "Although out of control, she proved a perfect sea ship and throughout the night never shipped a drop of water."Later in 1954, she was sold to BISCO and allocated to Thos W Ward. On 27 August she was delivered to Castle Pill for breaking up, in October her Grimsby registry was closed

Everybody Knows (film)

Everybody Knows is a 2018 Spanish-language psychological thriller film involving a criminal mystery and directed by Iranian filmmaker Asghar Farhadi, starring Javier Bardem and Penélope Cruz. The film opened the 2018 Cannes Film Festival in competition and was released in Spain on 14 September 2018, it was released in the United States on 8 February 2019. The story follows Laura, a Spanish woman living in Buenos Aires, who returns with her teenage daughter Irene and young son to her hometown outside Madrid for her younger sister's wedding. However, the trip is upset. Family decides not to involve police for the safety of Irene. Laura receives text messages from kidnappers demanding money against release of her daughter. Laura's brother in law, brings his friend, Jorge, a retired police office, for consultation. Jorge mentions. Laura's husband, Alejandro, is informed and he arrives to talk to the detective. Alejandro becomes upset when detective mentions his problems including alcoholism and bankruptcy.

In order to pursue Paco to pay ransom money by selling his estate, Laura tells him that Irene is his daughter. Paco is ready to sell his estate, but his wife doubts that Laura is lying about Irene's paternity as well as might be involved in the kidnapping to get money out of Paco because Laura sold her land to Paco years ago at below market rate. Detective tells Laura that whoever kidnapped Irene, knew that Paco was her father. Family starts to fall apart as it is revealed that because of Irene's fearless nature everybody felt Paco was her father. Laura's niece, goes to an abandoned house at night and meets with her boyfriend, it is revealed that she was the accomplice in the kidnapping, she begs her boyfriend to release Irene. Paco receives a voice message of Irene begging for help, he bring Irene Back. Laura and her family leave to go back to Argentina as Irene asks Alejandro why it was Paco who picked her up. Laura's older sister, who started suspecting her daughter, sits her husband down with her as the end credits roll.

Penélope Cruz as Laura and Ana’s sister, Alejandro’s wife, Irene’s mother and Antonio’s daughter Javier Bardem as Paco, Bea’s husband Ricardo Darín as Alejandro, Laura’s husband and Irene’s father Bárbara Lennie as Bea, Paco’s wife Inma Cuesta as Ana, Laura's younger sister, Irene’s aunt, Joan’s girlfriend and Antonio’s daughter Elvira Mínguez as Mariana, Laura's older sister, Irene’s aunt, Fernando’s wife, Antonio’s daughter and Rocio’s mother Eduard Fernández as Fernando, Mariana's husband and Rocio’s father Ramón Barea as Antonio, Ana and Laura's father and Irene’s grandfather Sara Sálamo as Rocío, Fernando's and Mariana's daughter Carla Campra as Irene, Laura's and Alejandro's daughter, Antonio’s granddaughter and Mariana’s niece Roger Casamajor as Joan, Ana's boyfriend José Ángel Egido as Jorge, a retired policeman Sergio Castellanos as Felipe, Irene's spanish friend Jaime Lorente as Luis Jordi Bosch The film is a French-Spanish-Italian co-production and received funding from Canal+, France Télévisions, Ciné+, l’ICAA, Movistar, among others.

Principal photography started in August 2017. The film had its world premiere at the Cannes Film Festival on 8 May 2018. Shortly after, Focus Features acquired distribution rights to the film in various territories, it screened at the Toronto International Film Festival on 8 September 2018. It was released in Spain on 14 September 2018, it was released in the United States on 8 February 2019. On review aggregator website Rotten Tomatoes, the film holds an approval rating of 77% based on 113 reviews, an average rating of 6.2/10. The Critics Consensus says: "Everybody Knows is somewhat less than the sum of its parts despite the efforts of an outstanding cast - and a disappointing step back for writer-director Asghar Farhadi". On the aggregator Metacritic, the film has a weighted average score of 68 out of 100, based on 16 critics, indicating "generally favorable reviews". Writing for The A. V. Club, A. A. Dowd gave the film a B rating, saying that "Javier Bardem and Penélope Cruz help break Cannes' opening-night curse".

Australian film site This Is Film awarded the film a positive review, with contributing critic Peter Gray stating it was “an absorbing, expertly-crafted thriller that continually holds your emotions at ransom”. The film was nominated in eight categories at the 33rd Goya Awards: Best Film, Best Director, Best Actor, Best Actress, Best Supporting Actor, Best Original Screenplay, Best Editing, Best Original Song. Official website Everybody Knows on IMDb Everybody Knows at Metacritic Everybody Knows at Rotten Tomatoes