Tiburon is an incorporated town in Marin County, California. It is located on the Tiburon Peninsula; the smaller city of Belvedere occupies the south-west part of the peninsula and is contiguous with Tiburon. Tiburon is bordered by Corte Madera to the north and Mill Valley to the west, but is otherwise surrounded by the Bay. Besides Belvedere and Tiburon, much of the peninsula is unincorporated, including portions of the north side and the communities of Strawberry and Paradise Cay; the population of Tiburon was 8,962 at the 2010 census. Belvedere and Tiburon share a post office; the city's name derives from the Spanish word tiburón, which means "shark". The name was first given to the peninsula on which the city is situated, inspired by the prevalence of locally native leopard sharks in the surrounding waters. Tiburon was the southern terminus of the San Francisco and North Pacific Railroad, which transported freight for transfer to barges for shipping to cities around San Francisco Bay, it is now a commuter and tourist town, linked by fast ferry services to San Francisco and with a concentration of restaurants and clothes shops.
It is the nearest mainland point to Angel Island and a regular ferry service connects to the island. Earliest human habitation of the local area was by Native Americans, who have left rock carvings on Ring Mountain. In 1884, the first post office in Tiburon opened. In 1964, Tiburon incorporated. Tiburon has Branwell Fanning. Much of the modern history material below is drawn from his "Brief History of Tiburon," published in the Town of Tiburon's General Plan. Tiburón means "shark" in Spanish. Whether Lt. Juan Manuel de Ayala saw a number of sharks near where he anchored the San Carlos in August 1775, off what is now Angel Island, or whether the tree-covered Tiburon Peninsula looked like a shark we may never know, he named the land Shark Point. The Coast Miwok Indians had lived here for thousands of years, but there is no clear concept of what they called the peninsula. John Reed, from Dublin, received a provisional grant for much of Southern Marin, including the Tiburon Peninsula, from the Mexican authorities in 1831, was formally granted the Rancho Corte Madera del Presidio in 1834.
Reed married Hilaria Sanchez, daughter of the commandante of the San Francisco Presidio in 1836. The Reed name is preserved on streets and the local school district. Various forms of Hilaria's name, that of her granddaughter Hilarita Reed, are found on streets, a housing development, the Catholic Church. Hilarita married Dr. Benjamin Lyford, who became the first land developer with his Lyford's Hygeia, now Old Tiburon; the Benjamin and Hilarita Lyford House located on their dairy farm on Strawberry Point, is now a feature of the Audubon Society's Western Headquarters and Sanctuary on Greenwood Beach Road. Life changed little in the 40 years between the death of John Reed in 1842 and the arrival of Peter Donahue in 1882. Donahue brought with him North Pacific Railroad, he made a deal with the Reed family for a right-of-way, blasted out the rock at Point Tiburon, built a railroad terminal to connect with ferries of San Francisco Bay. The passenger ferries took commuters and automobiles to San Francisco and Sausalito, while barges carried loaded freight cars to San Francisco and Richmond.
Wildflowers surround Old St. Hilary’s, Tiburon's iconic hillside landmark, a mission church named for St. Hilaire, Bishop of Poitiers; the heirs of John Reed — who held title to El Rancho Corte Madera del Presidio, the Mexican land grant that included the Tiburon Peninsula — deeded the one-quarter acre site for $2.00 to the Archdiocese of San Francisco, which built the church as a place of worship for local railroad workers in 1888. The church was deconsecrated to make way for a new, larger one and was headed for destruction until several individuals intent on preserving local history established the Landmarks Society and purchased the site and building in 1959, it has served as a schoolroom and town meeting hall and is now a popular setting for weddings and other memorable events. The last railroad operated passenger ferry left Tiburon in 1941, but the passenger and freight trains ran until 1967. Passenger ferry service was resumed in the 1960s when Harbor Carriers utilized sightseeing boats in the early morning and evening hours.
In the 1970s, the railroad removed trackage, plugged tunnels, demolished the trestle over Trestle Glen and railroad ferry pier. The railroad roadbed was purchased by the City of Tiburon and serves as the waterfront rail trail. After years of hearings and studies, the former railroad yards became the Point Tiburon housing and commercial project. During its heyday, the railroad-ferry service brought many other industries to Tiburon. Codfish canneries sprouted along the bay shore to can fish brought down from Alaska. Ship dismantlers broke up many obsolete ocean-going vessels. In 1904, the Navy established a huge coaling station on the east shore of the peninsula on the site of one of the old fish canneries. Brick kilns were built and several powder plants opened, oyster beds developed in the shallow waters of the bay; the rail yards were equipped to not only repair and service trains but to build passenger and freight cars and locomotives. Several of the largest San Francisco Bay ferries were built in the Tiburon yards.
The Navy coaling station has played a prominent part in the history of both Tiburon and Bay Area at large. Theodore Roosevelt's Great White Fleet was refueled there on its famous round-the-world cruise. Coaling
Hiking is the preferred term, in Canada and the United States, for a long, vigorous walk on trails, in the countryside, while the word walking is used for shorter urban walks. On the other hand, in the United Kingdom, the Republic of Ireland, the word "walking" is acceptable to describe all forms of walking, whether it is a walk in the park or backpacking in the Alps; the word hiking is often used in the UK, along with rambling and fell walking. The term bushwalking is endemic to Australia, having been adopted by the Sydney Bush Walkers club in 1927. In New Zealand a long, vigorous walk or hike is called tramping, it is a popular activity with numerous hiking organizations worldwide, studies suggest that all forms of walking have health benefits. In the United States, the Republic of Ireland, United Kingdom, hiking means walking outdoors on a trail, or off trail, for recreational purposes. A day hike refers to a hike. However, in the United Kingdom, the word walking is used, as well as rambling, while walking in mountainous areas is called hillwalking.
In Northern England, Including the Lake District and Yorkshire Dales, fellwalking describes hill or mountain walks, as fell is the common word for both features there. Hiking is sometimes referred to as such; this refers to difficult walking through dense forest, undergrowth, or bushes, where forward progress requires pushing vegetation aside. In extreme cases of bushwhacking, where the vegetation is so dense that human passage is impeded, a machete is used to clear a pathway; the Australian term bushwalking refers to both on and off-trail hiking. Common terms for hiking used by New Zealanders are walking or bushwalking. Trekking is the preferred word used to describe multi-day hiking in the mountainous regions of India, Nepal, North America, South America and the highlands of East Africa. Hiking a long-distance trail from end-to-end is referred to as trekking and as thru-hiking in some places. In North America, multi-day hikes with camping, are referred to as backpacking; the idea of taking a walk in the countryside for pleasure developed in the 18th century, arose because of changing attitudes to the landscape and nature associated with the Romantic movement.
In earlier times walking indicated poverty and was associated with vagrancy. Thomas West, an English priest, popularized the idea of walking for pleasure in his guide to the Lake District of 1778. In the introduction he wrote that he aimed to encourage the taste of visiting the lakes by furnishing the traveller with a Guide. To this end he included various'stations' or viewpoints around the lakes, from which tourists would be encouraged to enjoy the views in terms of their aesthetic qualities. Published in 1778 the book was a major success. Another famous early exponent of walking for pleasure, was the English poet William Wordsworth. In 1790 he embarked on an extended tour of France and Germany, a journey subsequently recorded in his long autobiographical poem The Prelude, his famous poem Tintern Abbey was inspired by a visit to the Wye Valley made during a walking tour of Wales in 1798 with his sister Dorothy Wordsworth. Wordsworth's friend Coleridge was another keen walker and in the autumn of 1799, he and Wordsworth undertook a three weeks tour of the Lake District.
John Keats, who belonged to the next generation of Romantic poets began, in June 1818, a walking tour of Scotland and the Lake District with his friend Charles Armitage Brown. More and more people undertook walking tours through the 19th century, of which the most famous is Robert Louis Stevenson's journey through the Cévennes in France with a donkey, recorded in his Travels with a Donkey. Stevenson published in 1876 his famous essay "Walking Tours"; the subgenre of travel writing produced many classics in the subsequent 20th century. An early American example of a book that describes an extended walking tour is naturalist John Muir's A Thousand Mile Walk to the Gulf, a posthumous published account of a long botanizing walk, undertaken in 1867. Due to industrialisation in England, people began to migrate to the cities where living standards were cramped and unsanitary, they would escape the confines of the city by rambling about in the countryside. However, the land in England around the urban areas of Manchester and Sheffield, was owned and trespass was illegal.
Rambling clubs soon sprang up in the north and began politically campaigning for the legal'right to roam'. One of the first such clubs, was'Sunday Tramps' founded by Leslie White in 1879; the first national grouping, the Federation of Rambling Clubs, was formed in London in 1905 and was patronized by the peerage. Access to Mountains bills, that would have legislated the public's'right to roam' across some private land, were periodically presented to Parliament from 1884 to 1932 without success. In 1932, the Rambler’s Right Movement organized a mass trespass on Kinder Scout in Derbyshire. Despite attempts on the part of the police to prevent the trespass from going ahead it was achieved due to massive publicity; however the Mountain Access Bill, passed in 1939 was opposed by many walkers' organizations, including The Ramblers, who felt that it did not
Sand is a granular material composed of finely divided rock and mineral particles. It is defined by size, being finer than coarser than silt. Sand can refer to a textural class of soil or soil type; the composition of sand varies, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal settings is silica in the form of quartz. The second most common type of sand is calcium carbonate, for example, created, over the past half billion years, by various forms of life, like coral and shellfish. For example, it is the primary form of sand apparent in areas where reefs have dominated the ecosystem for millions of years like the Caribbean. Sand is a non-renewable resource over human timescales, sand suitable for making concrete is in high demand. Desert sand, although plentiful, is not suitable for concrete, 50 billion tons of beach sand and fossil sand is needed each year for construction; the exact definition of sand varies.
The scientific Unified Soil Classification System used in engineering and geology corresponds to US Standard Sieves, defines sand as particles with a diameter of between 0.074 and 4.75 millimeters. By another definition, in terms of particle size as used by geologists, sand particles range in diameter from 0.0625 mm to 2 mm. An individual particle in this range size is termed a sand grain. Sand grains are between silt; the size specification between sand and gravel has remained constant for more than a century, but particle diameters as small as 0.02 mm were considered sand under the Albert Atterberg standard in use during the early 20th century. The grains of sand in Archimedes Sand Reckoner written around 240 BCE, were 0.02 mm in diameter. A 1953 engineering standard published by the American Association of State Highway and Transportation Officials set the minimum sand size at 0.074 mm. A 1938 specification of the United States Department of Agriculture was 0.05 mm. Sand feels gritty when rubbed between the fingers.
Silt, by comparison, feels like flour). ISO 14688 grades sands as fine and coarse with ranges 0.063 mm to 0.2 mm to 0.63 mm to 2.0 mm. In the United States, sand is divided into five sub-categories based on size: fine sand, fine sand, medium sand, coarse sand, coarse sand; these sizes are based on the Krumbein phi scale, where size in Φ = -log2D. On this scale, for sand the value of Φ varies from −1 to +4, with the divisions between sub-categories at whole numbers; the most common constituent of sand, in inland continental settings and non-tropical coastal settings, is silica in the form of quartz, because of its chemical inertness and considerable hardness, is the most common mineral resistant to weathering. The composition of mineral sand is variable, depending on the local rock sources and conditions; the bright white sands found in tropical and subtropical coastal settings are eroded limestone and may contain coral and shell fragments in addition to other organic or organically derived fragmental material, suggesting sand formation depends on living organisms, too.
The gypsum sand dunes of the White Sands National Monument in New Mexico are famous for their bright, white color. Arkose is a sand or sandstone with considerable feldspar content, derived from weathering and erosion of a granitic rock outcrop; some sands contain magnetite, glauconite or gypsum. Sands rich in magnetite are dark to black in color, as are sands derived from volcanic basalts and obsidian. Chlorite-glauconite bearing sands are green in color, as are sands derived from basaltic lava with a high olivine content. Many sands those found extensively in Southern Europe, have iron impurities within the quartz crystals of the sand, giving a deep yellow color. Sand deposits in some areas contain garnets and other resistant minerals, including some small gemstones. Rocks erode/weather over a long period of time by water and wind, their sediments are transported downstream; these sediments continue to break apart into smaller pieces. The type of rock the sediment originated from and the intensity of the environment gives different compositions of sand.
The most common rock to form sand is Granite, where the Feldspar minerals dissolve faster than the Quartz, causing the rock to break apart into small pieces. In high energy environments rocks break apart much faster than in more calm settings. For example, Granite rocks this means more Feldspar minerals in the sand because it wouldn't have had time to dissolve; the term for sand formed by weathering is epiclastic. Sand from rivers are collected either from the river itself or its flood plain, accounts for the majority of the sand used in the construction industry; because if this, many small rivers have been depleted, causing environmental concern and economic losses to adjacent land. The rate of sand mining in such areas outweighs the rate the sand can replenish, making it a non-renewable resource. Sand dunes are a consequence of wind deposition; the Sahara Desert is dry because of its geographic location and is known for its vast sand dunes. They exist here because little vegetation is able to grow and there's not a lot of water.
Over time, wind blow
San Francisco the City and County of San Francisco, is the cultural and financial center of Northern California. San Francisco is the 13th-most populous city in the United States, the fourth-most populous in California, with 884,363 residents as of 2017, it covers an area of about 46.89 square miles at the north end of the San Francisco Peninsula in the San Francisco Bay Area, making it the second-most densely populated large US city, the fifth-most densely populated U. S. county, behind only four of the five New York City boroughs. San Francisco is part of the fifth-most populous primary statistical area in the United States, the San Jose–San Francisco–Oakland, CA Combined Statistical Area; as of 2017, it was the seventh-highest income county in the United States, with a per capita personal income of $119,868. As of 2015, San Francisco proper had a GDP of $154.2 billion, a GDP per capita of $177,968. The San Francisco CSA was the country's third-largest urban economy as of 2017, with a GDP of $907 billion.
Of the 500+ primary statistical areas in the US, the San Francisco CSA had among the highest GDP per capita in 2017, at $93,938. San Francisco was ranked 14th in the world and third in the United States on the Global Financial Centres Index as of September 2018. San Francisco was founded on June 29, 1776, when colonists from Spain established Presidio of San Francisco at the Golden Gate and Mission San Francisco de Asís a few miles away, all named for St. Francis of Assisi; the California Gold Rush of 1849 brought rapid growth, making it the largest city on the West Coast at the time. San Francisco became a consolidated city-county in 1856. San Francisco's status as the West Coast's largest city peaked between 1870 and 1900, when around 25% of California's population resided in the city proper. After three-quarters of the city was destroyed by the 1906 earthquake and fire, San Francisco was rebuilt, hosting the Panama-Pacific International Exposition nine years later. In World War II, San Francisco was a major port of embarkation for service members shipping out to the Pacific Theater.
It became the birthplace of the United Nations in 1945. After the war, the confluence of returning servicemen, significant immigration, liberalizing attitudes, along with the rise of the "hippie" counterculture, the Sexual Revolution, the Peace Movement growing from opposition to United States involvement in the Vietnam War, other factors led to the Summer of Love and the gay rights movement, cementing San Francisco as a center of liberal activism in the United States. Politically, the city votes along liberal Democratic Party lines. A popular tourist destination, San Francisco is known for its cool summers, steep rolling hills, eclectic mix of architecture, landmarks, including the Golden Gate Bridge, cable cars, the former Alcatraz Federal Penitentiary, Fisherman's Wharf, its Chinatown district. San Francisco is the headquarters of five major banking institutions and various other companies such as Levi Strauss & Co. Gap Inc. Fitbit, Salesforce.com, Reddit, Inc. Dolby, Weebly, Pacific Gas and Electric Company, Pinterest, Uber, Mozilla, Wikimedia Foundation and Weather Underground.
It is home to a number of educational and cultural institutions, such as the University of San Francisco, University of California, San Francisco, San Francisco State University, the De Young Museum, the San Francisco Museum of Modern Art, the California Academy of Sciences. As of 2019, San Francisco is the highest rated American city on world liveability rankings; the earliest archaeological evidence of human habitation of the territory of the city of San Francisco dates to 3000 BC. The Yelamu group of the Ohlone people resided in a few small villages when an overland Spanish exploration party, led by Don Gaspar de Portolà, arrived on November 2, 1769, the first documented European visit to San Francisco Bay. Seven years on March 28, 1776, the Spanish established the Presidio of San Francisco, followed by a mission, Mission San Francisco de Asís, established by the Spanish explorer Juan Bautista de Anza. Upon independence from Spain in 1821, the area became part of Mexico. Under Mexican rule, the mission system ended, its lands became privatized.
In 1835, Englishman William Richardson erected the first independent homestead, near a boat anchorage around what is today Portsmouth Square. Together with Alcalde Francisco de Haro, he laid out a street plan for the expanded settlement, the town, named Yerba Buena, began to attract American settlers. Commodore John D. Sloat claimed California for the United States on July 7, 1846, during the Mexican–American War, Captain John B. Montgomery arrived to claim Yerba Buena two days later. Yerba Buena was renamed San Francisco on January 30 of the next year, Mexico ceded the territory to the United States at the end of the war. Despite its attractive location as a port and naval base, San Francisco was still a small settlement with inhospitable geography; the California Gold Rush brought a flood of treasure seekers. With their sourdough bread in tow, prospectors accumulated in San Francisco over rival Benicia, raising the population from 1,000 in 1848 to 25,000 by December 1849; the promise of great wealth was so strong that crews on arriving vessels deserted and rushed off to the gold fields, leaving behind a forest of masts in San Francisco harbor.
Some of these 500 abandoned ships were used at times as storeships and hotels.
Port of San Francisco
The Port of San Francisco is a semi-independent organization that oversees the port facilities at San Francisco, United States. It is run by a five-member commission, appointed by the Mayor and approved by the Board of Supervisors; the Port is responsible for managing the larger waterfront area that extends from the anchorage of the Golden Gate Bridge, along the Marina district, all the way around the north and east shores of the city of San Francisco including Fisherman's Wharf and the Embarcadero, southward to the city line just beyond Candlestick Point. In 1968 the State of California, via the California State Lands Commission for the State-operated San Francisco Port Authority, transferred its responsibilities for the Harbor of San Francisco waterfront to the City and County of San Francisco / San Francisco Harbor Commission through the Burton Act AB2649. All eligible State port authority employees had the option to become employees of the City and County of San Francisco to maintain consistent operation of the Port of San Francisco.
The Port of San Francisco lies on the western edge of the San Francisco Bay near the Golden Gate. It has been called one of the three great natural harbors in the world, but it took two long centuries for navigators from Spain and England to find the anchorage called Yerba Buena: a port, as was said in its early days, in which all the fleets of the world could find anchorage; the port area under the Commission's control comprises nearly eight miles of waterfront lands, commercial real estate and maritime piers from Hyde Street on the north to India Basin in the southeast. The list of landmarks under port control include Fisherman's Wharf, Pier 39, the Ferry Building, Oracle Park, located next to China Basin and Pier 70 at Potrero Point. Huge covered piers on piles jut out into San Francisco bay along much of the waterfront, bordered by the Embarcadero roadway. In 2015, the City, acting through the Port of San Francisco, launched the San Francisco Seawall Earthquake Safety and Disaster Prevention Program.
The first landing place on the north-eastern tip of the San Francisco peninsula was a rocky promontory below Telegraph Hill known as Clarke's Point that jutted into the San Francisco Bay at the line of what is now Broadway and Battery Streets. Yerba Buena Cove swept inland from the subsequently named Clarke's Point to as far as Montgomery Street to the west, further south and east to Rincon Point at the south of Market area at the foot of Folsom and Spear streets; the founding padres of Mission Dolores and the other northern California missions found the jetty at Clarke's Point a convenient landing for their commerce in hides and tallow. It is the same location where Russian ships anchored to load supplies of grain. Early European visitors were the British Raccoon in 1814 and the French frigate Artemise in 1839; the sloop USS St. Louis, which arrived in 1840, was the first warship to fly the American flag in San Francisco Bay. On July 9, 1846, the sloop USS Portsmouth gave a 21-gun salute and Captain John Berrien Montgomery and his detachment rowed ashore and hoisted the American flag on the Mexican flagpole in the small settlement's plaza named Portsmouth Square in honor of the ship.
The earliest development of a port in San Francisco, two and a half miles east of the Presidio, was under the Mexican regime, begun in 1835 as the town of Yerba Buena. Before this time, the port at Monterey was considered the official port of entry to California. Captain Richardson erected the first abode of a European on the hill overlooking the Bay, he became the first harbor master by appointment of the Governor Mariano Guadaloupe de Vallejo. Whalers took umbrage at the taxes charged by the Mexican governor Manuel Micheltorena in 1843, the outright banning of their trading in the port relocated from San Francisco to the Hawaiian Islands. Commodore John D. Sloat claimed California for the United States on July 7, 1846, during the Mexican–American War, Captain John B. Montgomery arrived to claim Yerba Buena two days later. In 1847, the first American alcalde, Lt. Washington Allon Bartlett changed the name from Yerba Buena to San Francisco, "so that the town may have the advantage of the name given on the public map."
The United States governor of the newly occupied territory of California, General Stephen W. Kearny, renounced the rights of eminent domain of the American government in favor of the city of San Francisco; the early city built up on the west side of Yerba Buena Cove around Portsmouth Square. The municipality of San Francisco was given the right, by General Kearney acting as governor of California, to sell "water lots" in the tidelands between Clarke's Point and Rincon Point so the city might gain revenues from the sale. At the same time, the owner of the land at the foot of Telegraph Hill, W. S. Clarke built a timbered wharf and the location became known as Clarke's Point. A substantial wharf 750 feet long and 60 feet wide was erected to the depth of water, 26 feet, made the landing available to deep water ships; this project was followed by other wharves built below Broadway and Clay streets, at Commercial street. When gold was discovered in California, the first hulk of an old iron revenue steamer, the James K. Polk, was beached at the foot of the bluff near Clarke's Point and became the foundation of the first real passenger landing in the city.
It was at this site that the population of San Francisco met the Pacific mail liner the Oregon to receive the official announcement that California had been admitted to the Union. The bluff at the point was leveled and on the land created a wharf was built that became the first regular berthing place, for a short t
Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another. The field of navigation includes four general categories: land navigation, marine navigation, aeronautic navigation, space navigation, it is the term of art used for the specialized knowledge used by navigators to perform navigation tasks. All navigational techniques involve locating the navigator's position compared to known locations or patterns. Navigation, in a broader sense, can refer to any skill or study that involves the determination of position and direction. In this sense, navigation includes pedestrian navigation. In the European medieval period, navigation was considered part of the set of seven mechanical arts, none of which were used for long voyages across open ocean. Polynesian navigation is the earliest form of open-ocean navigation, it was based on memory and observation recorded on scientific instruments like the Marshall Islands Stick Charts of Ocean Swells.
Early Pacific Polynesians used the motion of stars, the position of certain wildlife species, or the size of waves to find the path from one island to another. Maritime navigation using scientific instruments such as the mariner's astrolabe first occurred in the Mediterranean during the Middle Ages. Although land astrolabes were invented in the Hellenistic period and existed in classical antiquity and the Islamic Golden Age, the oldest record of a sea astrolabe is that of Majorcan astronomer Ramon Llull dating from 1295; the perfecting of this navigation instrument is attributed to Portuguese navigators during early Portuguese discoveries in the Age of Discovery. The earliest known description of how to make and use a sea astrolabe comes from Spanish cosmographer Martín Cortés de Albacar's Arte de Navegar published in 1551, based on the principle of the archipendulum used in constructing the Egyptian pyramids. Open-seas navigation using the astrolabe and the compass started during the Age of Discovery in the 15th century.
The Portuguese began systematically exploring the Atlantic coast of Africa from 1418, under the sponsorship of Prince Henry. In 1488 Bartolomeu Dias reached the Indian Ocean by this route. In 1492 the Spanish monarchs funded Christopher Columbus's expedition to sail west to reach the Indies by crossing the Atlantic, which resulted in the Discovery of the Americas. In 1498, a Portuguese expedition commanded by Vasco da Gama reached India by sailing around Africa, opening up direct trade with Asia. Soon, the Portuguese sailed further eastward, to the Spice Islands in 1512, landing in China one year later; the first circumnavigation of the earth was completed in 1522 with the Magellan-Elcano expedition, a Spanish voyage of discovery led by Portuguese explorer Ferdinand Magellan and completed by Spanish navigator Juan Sebastián Elcano after the former's death in the Philippines in 1521. The fleet of seven ships sailed from Sanlúcar de Barrameda in Southern Spain in 1519, crossed the Atlantic Ocean and after several stopovers rounded the southern tip of South America.
Some ships were lost, but the remaining fleet continued across the Pacific making a number of discoveries including Guam and the Philippines. By only two galleons were left from the original seven; the Victoria led by Elcano sailed across the Indian Ocean and north along the coast of Africa, to arrive in Spain in 1522, three years after its departure. The Trinidad sailed east from the Philippines, trying to find a maritime path back to the Americas, but was unsuccessful; the eastward route across the Pacific known as the tornaviaje was only discovered forty years when Spanish cosmographer Andrés de Urdaneta sailed from the Philippines, north to parallel 39°, hit the eastward Kuroshio Current which took its galleon across the Pacific. He arrived in Acapulco on October 8, 1565; the term stems from the 1530s, from Latin navigationem, from navigatus, pp. of navigare "to sail, sail over, go by sea, steer a ship," from navis "ship" and the root of agere "to drive". The latitude of a place on Earth is its angular distance north or south of the equator.
Latitude is expressed in degrees ranging from 0° at the Equator to 90° at the North and South poles. The latitude of the North Pole is 90° N, the latitude of the South Pole is 90° S. Mariners calculated latitude in the Northern Hemisphere by sighting the North Star Polaris with a sextant and using sight reduction tables to correct for height of eye and atmospheric refraction; the height of Polaris in degrees above the horizon is the latitude of the observer, within a degree or so. Similar to latitude, the longitude of a place on Earth is the angular distance east or west of the prime meridian or Greenwich meridian. Longitude is expressed in degrees ranging from 0° at the Greenwich meridian to 180° east and west. Sydney, for example, has a longitude of about 151° east. New York City has a longitude of 74° west. For most of history, mariners struggled to determine longitude. Longitude can be calculated. Lacking that, one can use a sextant to take a lunar distance that, with a nautical almanac, can be used to calculate the time at zero longitude.
Reliable marine chronometers were unavailable until the late 18th century and not affordable until the 19th century. For about a hundred years, from about 1767 until about 1850, mariners lacking a chronometer used the method of lunar distances to determine Greenwich time to find their longitude. A mariner with a chronometer could check its reading using a lunar determination of Greenwich tim
San Francisco Bay
San Francisco Bay is a shallow estuary in the US state of California. It is surrounded by a contiguous region known as the San Francisco Bay Area, is dominated by the large cities of San Jose, San Francisco and Oakland. San Francisco Bay drains water from 40 percent of California. Water from the Sacramento and San Joaquin rivers, from the Sierra Nevada mountains, flow into Suisun Bay, which travels through the Carquinez Strait to meet with the Napa River at the entrance to San Pablo Bay, which connects at its south end to San Francisco Bay; the Guadalupe River enters the bay at its southernmost point in San Jose. The Guadalupe drains water from the Santa Cruz mountains and Hamilton Mountain ranges in southernmost San Jose, it enters the bay at the town of Alviso. It connects to the Pacific Ocean via the Golden Gate strait. However, this entire group of interconnected bays is called the San Francisco Bay; the bay was designated a Ramsar Wetland of International Importance on February 2, 2012. The bay covers somewhere between 400 and 1,600 square miles, depending on which sub-bays, wetlands, so on are included in the measurement.
The main part of the bay measures three to twelve miles wide east-to-west and somewhere between 48 miles 1 and 60 miles 2 north-to-south. It is the largest Pacific estuary in the Americas; the bay was navigable as far south as San Jose until the 1850s, when hydraulic mining released massive amounts of sediment from the rivers that settled in those parts of the bay that had little or no current. Wetlands and inlets were deliberately filled in, reducing the Bay's size since the mid-19th century by as much as one third. Large areas of wetlands have been restored, further confusing the issue of the Bay's size. Despite its value as a waterway and harbor, many thousands of acres of marshy wetlands at the edges of the bay were, for many years, considered wasted space; as a result, soil excavated for building projects or dredged from channels was dumped onto the wetlands and other parts of the bay as landfill. From the mid-19th century through the late 20th century, more than a third of the original bay was filled and built on.
The deep, damp soil in these areas is subject to soil liquefaction during earthquakes, most of the major damage close to the Bay in the Loma Prieta earthquake of 1989 occurred to structures on these areas. The Marina District of San Francisco, hard hit by the 1989 earthquake, was built on fill, placed there for the Panama-Pacific International Exposition, although liquefaction did not occur on a large scale. In the 1990s, San Francisco International Airport proposed filling in hundreds more acres to extend its overcrowded international runways in exchange for purchasing other parts of the bay and converting them back to wetlands; the idea was, remains, controversial. There are five large islands in San Francisco Bay. Alameda, the largest island, was created when a shipping lane was cut to form the Port of Oakland in 1901, it is now a suburban community. Angel Island was known as "Ellis Island West" because it served as the entry point for immigrants from East Asia, it is now a state park accessible by ferry.
Mountainous Yerba Buena Island is pierced by a tunnel linking the east and west spans of the San Francisco–Oakland Bay Bridge. Attached to the north is the artificial and flat Treasure Island, site of the 1939 Golden Gate International Exposition. From the Second World War until the 1990s, both islands served as military bases and are now being redeveloped. Isolated in the center of the Bay is Alcatraz, the site of the famous federal penitentiary; the federal prison on Alcatraz Island no longer functions, but the complex is a popular tourist site. Despite its name, Mare Island in the northern part of the bay is a peninsula rather than an island. San Francisco Bay is thought to represent a down-warping of the Earth's crust between the San Andreas Fault to the west and the Hayward Fault to the east, though the precise nature of this remains under study. About 560,000 years ago, a tectonic shift caused the large inland Lake Corcoran to spill out the central valley and through the Carquinez Strait, carving out sediment and forming canyons in what is now the northern part of the San Francisco Bay and Golden Gate strait.
Until the last ice age, the basin, now filled by the San Francisco Bay was a large linear valley with small hills, similar to most of the valleys of the Coast Ranges. As the great ice sheets began to melt, around 11,000 years ago, the sea level started to rise. By 5000 BC the sea level rose 300 feet; the valley become a bay, the small hills became islands. From 15,000 – 10,000 years ago, the Ohlone tribe inhabited the area, now the San Francisco Bay; the natives were displaced 5,000 years ago as the bay filled with water due to the rising sea level at the end of the ice age. The first European to see San Francisco Bay is N. de Morena, left at New Albion at Drakes Bay in Marin County, California by Sir Francis Drake in 1579 and walked to Mexico. The first recorded European discovery of San Francisco Bay was on November 4, 1769 when Spanish explorer Gaspar de Portolà, unable to find the port of Monterey, continued north close to what is now Pacifica and reached the summit of the 1,200-foot-high Sweeney Ridge, now marked as the place where he first sighted San Francisco Bay.
Portolá and his party did not realize what they had discovered, thinking they had arrived at a large arm of what is now called Drakes Bay. At the time, Drakes Bay went by the name Bahia de San