Introduction to Oceanography

What is Oceanography?

• Oceanography is a multidisciplinary branch of science, studying the physical and biological properties of the sea
• An ocean is a large body of saltwater residing in depressions on the Earth's surface
• Oceans have artificial boundaries and divisions
• The concept of one world ocean suggests that the ocean divisions and boundaries are arbitrary

Earths water Coverage:

• Water covers 71% of Earth's surface
• About 97% of Earth’s water is contained in the salty ocean
• Only 3% is freshwater, with just 0.3% of that being viable for use
• Of the freshwater, 90% is held in ice caps, glaciers, and deep groundwater

Ocean Divisions

• The five main oceans are Pacific, Atlantic, Indian, Arctic, and Southern/Antarctic
• Sometimes can be divided into seven with North and South Atlantic and North and South Pacific
• Seas are generally smaller than oceans, peripheral to oceans and often partially enclosed by land
• Seas can be bordered by ridges, rises, and island chains and are often over continental margins

Ocean Facts

• The ocean's total surface area is 361,132,000 km²
• Total volume is 1,335,000,000 km³
• The average depth reaches 3,688 m
• The deepest point in the ocean measures 10,935 +/- 6m
• The Pacific Ocean basin is the Earth's largest feature and contains the world’s longest mountain chain

Deepest Part of The Ocean

• The Deepest Point of the Mariana Trench is called Challenger Deep
• It stretches from 10,903 to 10,989 m
• Measuring such depths is challenging, even with modern tools
• Most accurate recent measurement is 10,935 +/- 6 m
• The HMS Challenger (1872-1876) used a sounding machine to discover this

People who have been to Challenger Deep

• Piccard & Walsh in 1960
• Cameron in 2012
• Fen Dou Zhe, in 2020
• "Limiting Factor" x19 has been counting since 2019

Brief History of Ocean Exploration

• Oceans historically played a key role in facilitating, not preventing, human spread
• Ancient civilizations studied, traveled and explored the ocean for food, politics, power, wealth, and knowledge

Mediterranean Sea - Phoenician

• Circa 2000 BCE, Phoenicians navigated Africa by 590 BCE
• They established trade routes and developed distinct ship styles for trade and war
• Phoenicians ventured to the Atlantic, Red Sea, and Indian Ocean

Mediterranean Sea - Ancient Greeks & Egyptians

• These civilizations utilized the Mediterranean, Nile River, and Red Sea, advancing cartography

Ancient Greeks

• They built cargo ships, warships, and fishing vessels
• The Library of Alexandria became a repository of scientific knowledge, marking the start of marine science and flourishing cartography in the 3rd century BCE
• They contributed latitude and longitude: Pytheas used latitude based on the North Star’s angle, and Hipparchus developed the current grid system
• Eratosthenes, calculated Earth's circumference around 230 BC at 40,000 km and confirmed Earth’s round shape using shadows, day of year, and trigonometry

Ancient ‘Greeks & Romans

• Claudius Ptolemy published Geography in 150 AD, compiling geographical knowledge and he updated Eratosthenes’ circumference
• Ptolemy's inaccurate data later led Columbus to wrongly believe he had reached Asia instead of the Americas including the Caribbean

Ocean Exploration - Pacific - Polynesians

• The Oceanian culture led to the colonization of 'easiest' islands leading to overpopulation, religious warfare, and further exploration
• They used navigational techniques like stick charts (bamboo slats marked with shells) for wayfinding

Ocean Exploration - Antarctica

• Ui-te-Rangoria, a Polynesian Navigator, led a fleet south in 601-700 CE, reaching the frozen ocean after a small ice age in the 7th century C.E
• Sea ice may have migrated further north

Ocean Exploration - Pacific & Beyond - Chinese

• Admiral Zheng He undertook seven voyages from 1405-1433, commanding a fleet of 300+ treasure ships
• He implemented technical advancements for navigation like the compass
• He used a central rudder and watertight compartments, plus sails on multiple masts to support long voyages
• His crews had capability to distill seawater and grow fresh vegetables onboard, “collected” and cataloged cultural artifacts & scientific specimens

Ocean Exploration - Back to Europe - The Vikings

• Vikings built fast, stable ships ideal for the stormy North Atlantic
• They reached Iceland and Greenland from ships blown off course
• Erik “the Red” Thorvaldson settled Vinland in 995 AD, establishing L’Anse aux Meadows, led by Leif “the Lucky” Erikson

Ocean Exploration - [European] Age of “Discovery”

• French, English, Spanish, and Portuguese explorers had goals beyond exploration
• Key figures included Christopher Columbus, Prince Henry the Navigator, and Ferdinand Magellan whose ships completed circumnavigation of the globe by 1522
• This was an expansionist time with European powers seeking to expand empires & increase resources amidst wars

Voyages of Exploration

• Christopher Columbus's voyage reached South America and the Caribbean but made the wrong assumption about reaching India
• James Cook's voyages helped establish England's presence and he sailed to New Zealand, Hawaiian Islands, and Australia
• Cook explored the west coast of North America
• His charts in addition to his accurate navigation were used by Allied forces during WWII in the Pacific Islands

Onset of Trans-Atlantic Slave Trade

• Powers set up colonies to extract and ship back required workers
• West African slave traders sold captured Africans to European slavers
• Lack of quinine meant Europeans had short lives in Africa costing less than a year
• Portuguese slavers initiated trans-Atlantic voyages to Brazil in 1526
• An estimated 12.5 million slaves were transported from Africa to the Americas

Impact on Indigenous Peoples

• Colonial powers used the Doctrine of Discovery, a Roman Catholic Church edict, to claim land not populated by Christians using "Terra Nullius"
• In Canada, the pre-colonial population fell from 350,000-500,000+ to *125,000 by 1867
• The impacts were conflict, genocide, culture/ language loss and suppression, along with devastating "Old-World" viruses

Ocean Exploration - Scientific Expeditions

• The HMS Challenger (British Navy) undertook the first 'scientific' expedition with Canadian born Charles Wyville Thomson and John Murray
• It sailed December 21, 1872, taking a four-year voyage around the world pioneering use of the term oceanography
• Naval research played a critical role in Western oceanographic research from the 1900s to Present

Heroic Age of Antarctic Exploration

• The late 19th to early 20th century included 17 major exploration missions from 1887-1922
• These were strategic missions during WWI led by Belgians, British, Germans, Swedes, French, Japanese, Norwegians, & Australians
• Technology was developed and ships were designed for specific tasks

Glomar Challenger

• Designed in the late 1960s for drilling into and taking core samples from the deep ocean floor to study sediment cores
• Magnetic poles were marked in stone/ocean floor, helping understand plate tectonics

National Establishment of Research Institutions

• The Bedford Institute of Oceanography (BIO) is the largest ocean research station in Canada. It resides in Dartmouth, Nova Scotia
• The BIO conducted critical research during the Fukushima nuclear disaster, as well as transfer of radioactive isotopes across the ocean
• This occurred with the Department of Fisheries & Oceans
• This occurred with Environmental Climate Change Canada
• This also occurred with National Defence

Faces of Oceanography

• Sylvia Earlie, Chief Scientist at NOAA, completed several of the human kinds deepest dives
• Asha de Vos researches marine biology relating to blue whales and their poop in the Northern Indian Ocean

Ocean Origins

• All substances originate from particles forged in stars, including Earth, oceans & all living things
• The nuclear fusion reactors of the universe also create elements heavier than hydrogen and helium dispersed by supernovas

Big Bang

• The Big Bang is the term used to describe the start of the universe ~14 billion years ago
• In the first picosecond the Planck Epoch helped establish the 4 fundamental forces from gravity, electromagnetism, a strong nuclear force, and a weak nuclear force within an expanding space

Early Universe Development

• Subatomic particles formed within seconds to minutes and later the light ions formed
• At 10,000 to 100,000 years first proper atoms turned to first molecules
• At 370,000 years the universe became transparent creating the microwave background radiation (MBR)
• The process was accomplished when the first atoms reached “ground state” by releasing photons
• The sun was not one of the first stars- it formed after the supernova
• The dust cloud collapsed and injected materials from the supernova into the sun
• Earth formed by accretion *4.5-4.6 billion years ago and life appeared *3.7 Bya

Earth's Atmosphere & Oceans

• The First Atmosphere had very little atmosphere in the Hadean era and experienced too many collisions
• It mostly contained H, He, & other hydrogen gases were left over from contracting nebula
• High solar winds dispersed Earth’s 1st atmosphere since the Earth lacked a magnetic field
• The Second Atmosphere formed 4.2-3.8 billion years ago
• Earth's Second Atmosphere was formed when gases trapped in Earth were ‘burped' to the surface - outgassing
• The mainly CO2 and water vapour gasses were hot, rose, & eventually condensed into clouds
• Chemistry, gravity, and forming magnetic field formation prevented gases from escaping
• Oceans formed about 3.8 to 4.2 Bya
• Water vapour cooled & formed droplets, rain falling to earth and filling depressions

Volcanoes at the time

• There were many volcanic islands with the sun only 80-85% as bright
• H20, CO2, SO2, CH4 were common in the atmosphere
• The Great Oxidation Event around 2.4 Ga created Earth’s 3rd atmosphere assisting with life to start and grow

Life origins

• Cyanobacteria then photosynthesized, transforming CO2 into O2, thus supporting all other life to appear
• The Creation of life involved basic organic molecules (amino acids & nucleotides) being combined into complex molecules that replicate or reproduce by adding water and energy
• Stromatolites likely formed in hydrothermal vents with a chemical mixing pot to provide energy in the early deep ocean