Los Angeles the City of Los Angeles and known by its initials L. A. is the most populous city in California, the second most populous city in the United States, after New York City, the third most populous city in North America. With an estimated population of four million, Los Angeles is the cultural and commercial center of Southern California; the city is known for its Mediterranean climate, ethnic diversity and the entertainment industry, its sprawling metropolis. Los Angeles is the largest city on the West Coast of North America. Los Angeles is in a large basin bounded by the Pacific Ocean on one side and by mountains as high as 10,000 feet on the other; the city proper, which covers about 469 square miles, is the seat of Los Angeles County, the most populated county in the country. Los Angeles is the principal city of the Los Angeles metropolitan area, the second largest in the United States after that of New York City, with a population of 13.1 million. It is part of the Los Angeles-Long Beach combined statistical area the nation's second most populous area with a 2015 estimated population of 18.7 million.
Los Angeles is one of the most substantial economic engines within the United States, with a diverse economy in a broad range of professional and cultural fields. Los Angeles is famous as the home of Hollywood, a major center of the world entertainment industry. A global city, it has been ranked 6th in the Global Cities Index and 9th in the Global Economic Power Index; the Los Angeles metropolitan area has a gross metropolitan product of $1.044 trillion, making it the third-largest in the world, after the Tokyo and New York metropolitan areas. Los Angeles hosted the 1932 and 1984 Summer Olympics and will host the event for a third time in 2028; the city hosted the Miss Universe pageant twice, in 1990 and 2006, was one of 9 American cities to host the 1994 FIFA men's soccer World Cup and one of 8 to host the 1999 FIFA women's soccer World Cup, hosting the final match for both tournaments. Home to the Chumash and Tongva, Los Angeles was claimed by Juan Rodríguez Cabrillo for Spain in 1542 along with the rest of what would become Alta California.
The city was founded on September 4, 1781, by Spanish governor Felipe de Neve. It became a part of Mexico in 1821 following the Mexican War of Independence. In 1848, at the end of the Mexican–American War, Los Angeles and the rest of California were purchased as part of the Treaty of Guadalupe Hidalgo, becoming part of the United States. Los Angeles was incorporated as a municipality on April 4, 1850, five months before California achieved statehood; the discovery of oil in the 1890s brought rapid growth to the city. The completion of the Los Angeles Aqueduct in 1913, delivering water from Eastern California assured the city's continued rapid growth; the Los Angeles coastal area was settled by the Chumash tribes. A Gabrieleño settlement in the area was called iyáangẚ, meaning "poison oak place". Maritime explorer Juan Rodríguez Cabrillo claimed the area of southern California for the Spanish Empire in 1542 while on an official military exploring expedition moving north along the Pacific coast from earlier colonizing bases of New Spain in Central and South America.
Gaspar de Portolà and Franciscan missionary Juan Crespí, reached the present site of Los Angeles on August 2, 1769. In 1771, Franciscan friar Junípero Serra directed the building of the Mission San Gabriel Arcángel, the first mission in the area. On September 4, 1781, a group of forty-four settlers known as "Los Pobladores" founded the pueblo they called El Pueblo de Nuestra Señora la Reina de los Ángeles,'The Town of Our Lady the Queen of the Angels'; the present-day city has the largest Roman Catholic Archdiocese in the United States. Two-thirds of the Mexican or settlers were mestizo or mulatto, a mixture of African and European ancestry; the settlement remained a small ranch town for decades, but by 1820, the population had increased to about 650 residents. Today, the pueblo is commemorated in the historic district of Los Angeles Pueblo Plaza and Olvera Street, the oldest part of Los Angeles. New Spain achieved its independence from the Spanish Empire in 1821, the pueblo continued as a part of Mexico.
During Mexican rule, Governor Pío Pico made Los Angeles Alta California's regional capital. Mexican rule ended during the Mexican–American War: Americans took control from the Californios after a series of battles, culminating with the signing of the Treaty of Cahuenga on January 13, 1847. Railroads arrived with the completion of the transcontinental Southern Pacific line to Los Angeles in 1876 and the Santa Fe Railroad in 1885. Petroleum was discovered in the city and surrounding area in 1892, by 1923, the discoveries had helped California become the country's largest oil producer, accounting for about one-quarter of the world's petroleum output. By 1900, the population had grown to more than 102,000; the completion of the Los Angeles Aqueduct in 1913, under the supervision of William Mulholland, assured the continued growth of the city. Due to clauses in the city's charter that prevented the City of Los Angeles from selling or providing water from the aqueduct to any area outside its borders, many adjacent city and communities became compelled to annex themselves into Los Angeles.
Los Angeles created the first municipal zoning ordinance in the United States. On September 14, 1908, the Los Angeles City Council promulgated residential and industrial land use zones; the new ordinance established three residential zones of a single type, where industrial uses were
The Holocene is the current geological epoch. It began 11,650 cal years before present, after the last glacial period, which concluded with the Holocene glacial retreat; the Holocene and the preceding Pleistocene together form the Quaternary period. The Holocene has been identified with the current warm period, known as MIS 1, it is considered by some to be an interglacial period within the Pleistocene Epoch. The Holocene has seen the growth and impacts of the human species worldwide, including all its written history, development of major civilizations, overall significant transition toward urban living in the present. Human impacts on modern-era Earth and its ecosystems may be considered of global significance for future evolution of living species, including synchronous lithospheric evidence, or more hydrospheric and atmospheric evidence of human impacts. In July 2018, the International Union of Geological Sciences split the Holocene epoch into three distinct subsections, Greenlandian and Meghalayan, as proposed by International Commission on Stratigraphy.
The boundary stratotype of Meghalayan is a speleothem in Mawmluh cave in India, the global auxiliary stratotype is an ice core from Mount Logan in Canada. The name Holocene comes from the Ancient Greek words ὅλος and καινός, meaning "entirely recent", it is accepted by the International Commission on Stratigraphy that the Holocene started 11,650 cal years BP. The Subcommission on Quaternary Stratigraphy quotes Gibbard and van Kolfschoten in Gradstein Ogg and Smith in stating the term'Recent' as an alternative to Holocene is invalid and should not be used and observe that the term Flandrian, derived from marine transgression sediments on the Flanders coast of Belgium has been used as a synonym for Holocene by authors who consider the last 10,000 years should have the same stage-status as previous interglacial events and thus be included in the Pleistocene; the International Commission on Stratigraphy, considers the Holocene an epoch following the Pleistocene and the last glacial period. Local names for the last glacial period include the Wisconsinan in North America, the Weichselian in Europe, the Devensian in Britain, the Llanquihue in Chile and the Otiran in New Zealand.
The Holocene can be subdivided into five time intervals, or chronozones, based on climatic fluctuations: Preboreal, Atlantic and Subatlantic. Note: "ka" means "kilo-annum" Before Present, i.e. 1,000 years before 1950 The Blytt–Sernander classification of climatic periods defined by plant remains in peat mosses, is being explored. Geologists working in different regions are studying sea levels, peat bogs and ice core samples by a variety of methods, with a view toward further verifying and refining the Blytt–Sernander sequence, they find a general correspondence across Eurasia and North America, though the method was once thought to be of no interest. The scheme was defined for Northern Europe, but the climate changes were claimed to occur more widely; the periods of the scheme include a few of the final pre-Holocene oscillations of the last glacial period and classify climates of more recent prehistory. Paleontologists have not defined any faunal stages for the Holocene. If subdivision is necessary, periods of human technological development, such as the Mesolithic and Bronze Age, are used.
However, the time periods referenced by these terms vary with the emergence of those technologies in different parts of the world. Climatically, the Holocene may be divided evenly into the Neoglacial periods. According to some scholars, a third division, the Anthropocene, has now begun; the International Commission on Stratigraphy Subcommission on Quaternary Stratigraphy’s working group on the'Anthropocene' note this term is used to denote the present time interval in which many geologically significant conditions and processes have been profoundly altered by human activities. The'Anthropocene' is not a formally defined geological unit. Continental motions due to plate tectonics are less than a kilometre over a span of only 10,000 years. However, ice melt caused world sea levels to rise about 35 m in the early part of the Holocene. In addition, many areas above about 40 degrees north latitude had been depressed by the weight of the Pleistocene glaciers and rose as much as 180 m due to post-glacial rebound over the late Pleistocene and Holocene, are still rising today.
The sea level rise and temporary land depression allowed temporary marine incursions into areas that are now far from the sea. Holocene marine fossils are known, from Vermont and Michigan. Other than higher-latitude temporary marine incursions associated with glacial depression, Holocene fossils are found in lakebed and cave deposits. Holocene marine deposits along low-latitude coastlines are rare because the rise in sea levels during the period exceeds any tectonic uplift of non-glacial origin. Post-glacial rebound in the Scandinavia region resulted in the formation of the Baltic Sea; the region continues to rise, still causing weak earthquakes across Northern Europe. The equivalent event in North America was the rebound of Hudson Bay, as it shrank from its larger, immediate post-glacial Tyrrell Sea phase, to near its present boundaries. Climate has been stable over the Holocene. Ice core
Port of Los Angeles
The Port of Los Angeles called America's Port, is a port complex that occupies 7,500 acres of land and water along 43 miles of waterfront and adjoins the separate Port of Long Beach. The port is located in San Pedro Bay in the San Pedro and Wilmington neighborhoods of Los Angeles 20 miles south of downtown. A department of the City of Los Angeles, the Port of Los Angeles supports employment for 517,000 people throughout the LA County Region and 1.6 million worldwide. The cargo coming into the port represents 20% of all cargo coming into the United States; the Port's Channel Depth is 53 feet. The port has 27 cargo terminals, 86 container cranes, 8 container terminals, 113 miles of on-dock rail; the LA Port imports furniture, electronics, automobile parts, plastics. The Port exports wastepaper and animal feed, scrap metal and soybeans; the port's major trading partners are China, Hong Kong, South Korea and Vietnam. For public safety, the Port of Los Angeles utilizes the Los Angeles Port Police for police service in the port and to its local communities, the Los Angeles Fire Department to provide fire and EMS services to the port and its local communities, the U.
S. Coast Guard for water way security at the port, Homeland Security to protect federal land at the port, the Los Angeles County Lifeguards to provide lifeguard services for open water outside the harbor while Los Angeles City Recreation & Parks Department lifeguards patrol the inner Cabrillo Beach. In 1542, Juan Rodriquez Cabrillo discovered the "Bay of Smokes." The south-facing San Pedro Bay was a shallow mudflat, too soft to support a wharf. Visiting ships had two choices: stay far out at anchor and have their goods and passengers ferried to shore, or beach themselves; that sticky process is described in Two Years Before the Mast by Richard Henry Dana, Jr., a crew member on an 1834 voyage that visited San Pedro Bay. Phineas Banning improved shipping when he dredged the channel to Wilmington in 1871 to a depth of 10 feet; the port handled 50,000 tons of shipping that year. Banning owned a stagecoach line with routes connecting San Pedro to Salt Lake City and Yuma, in 1868 he built a railroad to connect San Pedro Bay to Los Angeles, the first in the area.
After Banning's death in 1885, his sons pursued their interests in promoting the port, which handled 500,000 tons of shipping in that year. The Southern Pacific Railroad and Collis P. Huntington wanted to create Port Los Angeles at Santa Monica and built the Long Wharf there in 1893. However, the Los Angeles Times publisher Harrison Gray Otis and U. S. Senator Stephen White pushed for federal support of the Port of Los Angeles at San Pedro Bay; the Free Harbor Fight was settled when San Pedro was endorsed in 1897 by a commission headed by Rear Admiral John C. Walker. With U. S. government support, breakwater construction began in 1899, the area was annexed to Los Angeles in 1909. The Los Angeles Board of Harbor Commissioners was founded in 1907. In 1912 the Southern Pacific Railroad completed its first major wharf at the port. During the 1920s, the port surpassed San Francisco as the West Coast's busiest seaport. In the early 1930s, a massive expansion of the port was undertaken with the construction of a breakwater three miles out and over two miles in length.
In addition to the construction of this outer breakwater, an inner breakwater was built off Terminal Island with docks for seagoing ships and smaller docks built at Long Beach. It was this improved harbor. During World War II, the port was used for shipbuilding, employing more than 90,000 people. In 1959, Matson Navigation Company's Hawaiian Merchant delivered 20 containers to the port, beginning the port's shift to containerization; the opening of the Vincent Thomas Bridge in 1963 improved access to Terminal Island and allowed increased traffic and further expansion of the port. In 1985, the port handled one million containers in a year for the first time. In 2000, the Pier 400 Dredging and Landfill Program, the largest such project in America, was completed. By 2013, more than half a million containers were moving through the Port every month. Since 2018, the SpaceX BFR, designed for human missions to Mars, is being produced in a factory at the port; the port district is an independent, self-supporting department of the government of the City of Los Angeles.
The port is under the control of a five-member Board of Harbor Commissioners appointed by the mayor and approved by the city council, is administered by an executive director. The port maintains the highest rating attainable for self-funded ports; the port has about a dozen pilots, including two chiefs. Pilots have specialized knowledge of San Pedro Bay, they meet the ships waiting to enter the harbor and provide advice as the vessel is steered through the congested waterway to the dock. The port's container volume was 9.3 million twenty-foot equivalent units in calendar year 2017, a 5.5% increase over 2016's record-breaking year of 8.8 million TEU. It's the most cargo moved annually by a Western Hemisphere port; the port is the busiest port in the United States by container volume, the 19th-busiest container port in the world, the 10th-busiest worldwide when combined with the neighboring Port of Long Beach. The port is the number-one freight gateway in the United States when ranked by the value of shipments passing through it.
The port's top trading partners in 2016 were: China/Hong Kong Japan Vietnam South Korea Tai
Anacapa Island is a small volcanic island located about 11 miles off the coast of Port Hueneme, California, in Ventura County. The island is composed of a series of narrow islets 6 mi long, oriented east-west and 5 mi east of Santa Cruz Island; the three main islets, East and West Anacapa, are collectively known as The Anacapas by some authors. All three islets have precipitous cliffs. Anacapa is the smallest of the northern islands of the Channel Islands archipelago, is within the Channel Islands National Park, it is 9 miles across the Santa Barbara Channel from the nearest point on the mainland. It lies southwest of the city of Ventura. Along with Santa Barbara Island, Anacapa was formed by volcanic eruptions between 19 and 15 million years ago; these eruptions are believed to have been caused by thinning of ocean crust as the block containing the northern Channel Islands and Santa Monica mountains was rotated clockwise by the transverse motion of the Pacific and North American plates. Lava from these eruptions can be found across the region, in depths of up to 10,000 feet.
The rocks that make up Anacapa are composed of lava, volcanic ash and cinders. Erosion has weathered the lava formations of Anacapa, wave action caused the island to split into three islets in recent prehistoric times; the islets display a wide variety of erosional features including sea arches, sea caves, wave-cut platforms, surge channels and blowholes. West Anacapa is the largest and highest islet, rising to an altitude of 930 ft at Vela Peak known as Summit Peak 2. East and Middle Anacapa have level areas at their tops. Middle Island reaches an altitude of 325 ft and East Island is 250 ft at its highest point. All three islands total about 1.1 square miles. East Island's most notable natural feature is a 40-foot - high natural bridge; as as the end of the last ice age, sea levels as much as 400 ft lower meant that the four northern Channel Islands were part of a single large island that lay about 5 miles off the California coast. Fossils of pygmy mammoths from this Late Pleistocene period 13,000 years ago have been found on the other three northern islands and it is reasonable to assume pygmy mammoths were present on Anacapa.
In The Channel Islands of California, Charles Frederick Holder says of Anacapa: Arid appearing, wind-swept, Anacapa is withal a valuable possession to its owner, one of the picturesque islands of the entire group. Its strange rocks, passing, made a strong impression on my mind, an impression of warring nature, conflicts of wind and rock, of seas eating into its vitals, of caves that undermine it, of the old rock fighting for its life against the sea. Anacapa Island, located only about 11 mi from the urbanized coast of Southern California, provides critical habitat for seabirds, pinnipeds such as California sea lions, several endemic plants and animals. Great white sharks, feeding on pinnipeds, are found in the waters of the Channel Islands, including Anacapa; the island has a somewhat diverse flora, including around 150 native plants, including 16 endemics plus many introduced species. Anacapa has around 69 species of birds; the island's steep lava rock cliffs incorporate numerous caves and crevices that are important for the rare seabird Scripps's murrelet.
The cliffs are an important location for the ashy storm-petrel. The largest breeding colony of the California brown pelican in the United States, one of the only two in California occurs on Anacapa Island; this is where the brown pelican has been able to recover so from near extinction in the 1970s. The islets of Anacapa host the largest breeding colony of western gulls in the world. Western gulls begin their nesting efforts at the end of April, sometimes making their shallow nests just inches from trails. Fluffy chicks fly away from the nests in July; the only native land mammal on the island is a unique subspecies of deer mouse which occurs on all three islets, but nowhere else. Anacapa has two native reptiles: an endemic form of the interesting and attractive side-blotched lizard. There is the Channel Islands slender salamander. Marine mammals and other marine life abound on Anacapa. Anacapa's prolific and dense vegetation was once dominated by the showy giant coreopsis named Coreopsis gigantea, an erect, shrubby perennial with a stout, succulent trunk growing to some 8 ft tall.
The main trunk grows up to 5 in thick and resembles a small tree. During its blooming season, March to May, it bursts forth with a mass of showy, bright yellow flowers and green leaves. Giant coreopsis provided shelter and perches for seabirds and land birds, nesting habitat for many; the prolific seeds provided abundant food for the endemic Anacapa deer mouse, for many small birds. The island's stands of giant coreopsis, as well as all the other plants of its coastal bluff community, were devastated by sheep grazing in the late 1800s and early 1900s, rabbit browsing in 1910-1950s, by large-scale destruction of native vegetation associated with fa
Ellwood Oil Field
Ellwood Oil Field and South Ellwood Offshore Oil Field are a pair of adjacent active oil fields adjoining the city of Goleta, about twelve miles west of Santa Barbara in the Santa Barbara Channel. A richly productive field in the 1930s, the Ellwood Oil Field was important to the economic development of the Santa Barbara area; the Japanese submarine I-17 shelled the area during World War II, the first direct naval bombardment of the U. S. mainland of the war, causing an invasion scare on the West Coast. The Ellwood Oil Field is located 12 miles west of the city of Santa Barbara, beginning at the western boundary of the city of Goleta, proceeding west into the Pacific and back onshore near Dos Pueblos Ranch; the onshore portions of the field include beach, coastal bluffs, blufftop grasslands, eucalyptus groves. Some of the former oil field is now part of the Ellwood-Devereux Open Space, maintained by the city of Goleta, the Bacara Resort, Sandpiper Golf Course, new Goleta housing developments sit on areas occupied by pump-jacks and oil storage tanks.
The climate is Mediterranean, with an equable temperature regime year-round, most of the precipitation falling between October and April in the form of rain. Freezes are rare. Runoff is towards the ocean, to a few vernal pools on the bluffs; the offshore portions of the Ellwood oil field are in shallow water, were drilled from piers. The South Ellwood Offshore field is beneath the Pacific Ocean, about two miles from the main onshore oil field, it is within the State Tidelands zone, which encompasses areas within three nautical miles of shore. These regions are subject to state, rather than Federal regulation; the only production from this field is from Platform Holly, in 211 feet of water, about two miles from the coast at Coal Oil Point. Numerous directionally-drilled oil wells originate at the platform, several pipelines connect the platform to an onshore oil processing facility adjacent to the Sandpiper Golf Course; the Ellwood Oil Field is five miles long and up to a mile wide, with both its eastern and western extremity onshore.
It is an anticlinal structure, with oil trapped stratigraphically by the anticline. The More Ranch Fault provides an impermeable barrier on the northeast. Oil occurs in several pools, with the largest being in the Vaqueros Sandstone 3,400 feet below ground surface. Other significant pools occur in the Rincon Formation at a depth of 2,600 feet, in the Upper Sespe Formation at 3,700 feet below ground surface; the Ellwood Oil Field contained 106 million barrels of oil all of, removed, to the degree possible with the technology available until the early 1970s. The field now has been abandoned; the South Ellwood Offshore field, on the other hand, has been estimated by the US Department of Energy to hold over one billion barrels of oil and 2.1 billion barrels by Venoco, Inc. most of, in the undeveloped portion of the field. In 1995, the Oil and Gas Journal reported 155 million barrels of proven reserves. Oil from the Ellwood field was light and sweet, with an API gravity averaging 38 and low sulfur content.
Oil from the offshore field is medium-grade, ranging from API gravity 25 to 34, has a higher sulfur content, requiring more processing than the oil from the decommissioned onshore field. Several pools have been identified in the South Ellwood Offshore field, in three major vertical zones; the upper Monterey Formation contains a large pool in a zone of fractured shale at an average depth of 3,350 feet below the ocean floor. Beneath that, a separate pool exists in the Rincon Sand, 5,000 feet below the ocean floor, yet another in the Vaqueros Formation at a depth of 5,900 feet; the deepest well drilled to date is 6,490 feet into the Rincon Formation: age and strata information are still company-confidential to Venoco, the current operator. This was a short-lived oil field which produced for only 13 months before water appeared in the wells. Production ceased by Feb. 1928. Miley Oil Company drilled the No. Goleta 1 discovery well, with oil shows at 1,527 feet; the field is named for Ellwood Cooper, who owned the large Ellwood Ranch in what is now Goleta and the adjacent hills.
His first name lingers in several local place names including the oil fields, Ellwood Canyon, Ellwood School, Ellwood Station Road, the Goleta neighborhood "Ellwood". The first oil discovery in the area was in July 1928, by Barnsdall Oil Co. of California and the Rio Grande Company, who drilled their Luton-Bell Well No. 1 to a depth of 3,208 feet into the Vaqueros Sandstone. After giving up they not only struck oil, but had a significant gusher producing 1,316 barrels per day; this discovery touched off a period of oil leasing and wildcat well drilling on the Santa Barbara south coast, from Carpinteria to Gaviota. During this period, the Mesa Oil Field was discovered, within the Santa Barbara city limits, about 12 miles east of the Ellwood field. See the Bombardment of Ellwood A consequential visit by a foreigner occurred in the late 1930s. Kozo Nishino, the skipper of a Japanese oil tanker, visited the field to load oil. While walking with his crew to a formal welcoming ceremony onshore, he tripped and fell into a patch of prickly pear cactus.
The sight of the proud Japanese commander having cactus spines pulled from his buttocks provoked laughter
The humpback whale is a species of baleen whale. One of the larger rorqual species, adults range in length from 12–16 m and weigh around 25–30 metric tons; the humpback has a distinctive body shape, with a knobbly head. It is known for breaching and other distinctive surface behaviors, making it popular with whale watchers. Males produce a complex song lasting 10 to 20 minutes, its purpose is not clear. Found in oceans and seas around the world, humpback whales migrate up to 25,000 km each year, they feed in polar waters, migrate to tropical or subtropical waters to breed and give birth and living off their fat reserves. Their diet consists of krill and small fish. Humpbacks have a diverse repertoire of feeding methods, including the bubble net technique. Like other large whales, the humpback was a target for the whaling industry. Once hunted to the brink of extinction, its population fell by an estimated 90% before a 1966 moratorium. While stocks have recovered to some 80,000 animals worldwide, entanglement in fishing gear, collisions with ships and noise pollution continue to impact on the species.
Humpback whales are rorquals, members of the Balaenopteridae family that includes the blue, Bryde's, sei and minke whales. The rorquals are believed to have diverged from the other families of the suborder Mysticeti as long ago as the middle Miocene era. However, it is not known. Though related to the giant whales of the genus Balaenoptera, the humpback is the sole member of its genus. Recent DNA sequencing has indicated the humpback is more related to certain rorquals the fin whale and the gray, than it is to others such as the minke; the humpback was first identified as baleine de la Nouvelle Angleterre by Mathurin Jacques Brisson in his Regnum Animale of 1756. In 1781, Georg Heinrich Borowski described the species, converting Brisson's name to its Latin equivalent, Balaena novaeangliae. In 1804, Lacépède shifted the humpback from the family Balaenidae. In 1846, John Edward Gray created the genus Megaptera, classifying the humpback as Megaptera longipinna, but in 1932, Remington Kellogg reverted the species names to use Borowski's novaeangliae.
The common name is derived from the curving of their backs. The generic name Megaptera from the Greek mega-/μεγα- "giant" and ptera/πτερα "wing", refers to their large front flippers; the specific name means "New Englander" and was given by Brisson due to regular sightings of humpbacks off the coast of New England. Genetic research in mid-2014 by the British Antarctic Survey confirmed that the separate populations in the North Atlantic, North Pacific and Southern Oceans are more distinct than thought; some biologists believe that these should be regarded as separate subspecies and that they are evolving independently. Humpbacks can be identified by their stocky body, obvious hump, black dorsal coloring and elongated pectoral fins; the head and lower jaw are covered with knobs called tubercles, which are hair follicles and are characteristic of the species. The fluked tail, which rises above the surface when diving, has wavy trailing edges. Humpbacks have 270 to 400 darkly colored baleen plates on each side of their mouths.
The plates measure from 18 in in the front to about 3 ft in the back, behind the hinge. Ventral grooves run from the lower jaw to the umbilicus, about halfway along the underside of the body; these grooves are less numerous than in other rorquals, but are wide. The female has a hemispherical lobe about 15 cm in diameter in her genital region; this visually distinguishes females. The male's penis remains hidden in the genital slit. Grown males average 13–14 m. Females are larger at 15–16 m; the largest humpback on record, according to whaling records, was a female killed in the Caribbean. The largest measured by the scientists of the Discovery Committee were a female 14.9 m and a male 14.75 m, although this was out of a sample size of only 63 whales. Body mass is in the range of 25–30 metric tons, with large specimens weighing over 40 metric tons. Newborn calves are the length of their mother's head. At birth, calves measure 6 m at 2 short tons, they nurse for about six months mix nursing and independent feeding for six months more.
Humpback milk is 50 % pink in color. Females reach sexual maturity at age five. Males reach sexual maturity around seven years of age; the long black and white tail fin can be up to a third of body length. Several hypotheses attempt to explain the humpback's pectoral fins, which are proportionally the longest fins of any cetacean; the higher maneuverability afforded by long fins and the usefulness of the increased surface area for temperature control when migrating between warm and cold climates supported this adaptation. The varying patterns on the tail flukes distinguish individual animals. A study using data from 1973 to 1998 on whales in the North Atlantic gave researchers detailed information on gestation times, growth rates and calving periods, as well as allowing