Introduction to Oceanography Professor Marianne E. McNamara

First, An icebreaker… Your major Your year/Part time or full time Your plans Your objectives Your interests

What is oceanography? Oceanography is the study of the ocean An interdisciplinary science: Geology Geography Chemistry Physics Biology Astronomy

What is oceanography? Oceanography consists of several specialized disciplines Marine Biology (Biological oceanography) Chemical Oceanography Geological Oceanography Physical Oceanography Marine Engineering Marine Ecology Marine Management

Oceanography ≠ Dolphins! Chemical Oceanography Biological Oceanography Physical Oceanography Geological Oceanography

…but it is one way to unleash your inner dolphin hugger… Yours truly

Got Ocean? The ocean covers 71% of the Earth’s surface Accounts for >97% of the Earth’s water! That means that all the rivers, lakes, glaciers, rain, snow, and groundwater make up the <3% remainder! The average depth of the ocean is 3,800 meters (=12,500 feet) and at its deepest depth is 7,000 ft greater than the highest elevation on land (Mt. Everest 29,000 ft; Mariana Trench 36,163 ft) The average temperature of the ocean is only 3.9 ̊C (=39 ̊F)

Oceanography For our convenience, the oceans are separated into 5 named ocean basins (and many smaller seas), but they all constitute one world ocean; one great intermixing mass of saline (salty) water All oceans are, in fact, interconnected with one another

One World Ocean Pacific Ocean (the largest) Atlantic Ocean Indian Ocean Arctic Ocean Southern Ocean

One World Ocean Arctic Ocean Atlantic Ocean Pacific Ocean Indian Ocean Southern Ocean http://www.gebco.net/data_and_products/gebco_world_map/images/gda_world_map_large.jpg

The Ocean’s Origins The Earth is believed to be 4.6 billion years old During the Earth’s formation, heavy (dense) metals such as iron and nickel gravitated towards the hot center in a molten state At the same time, lighter elements such as aluminum and silicon rose towards the surface, forming the Earth’s crust

The Ocean’s Origins Crust is made up of different rock types, and so is thinner and thicker in places Thick = land; thin = ocean!

The Ocean’s Origins Eventually, the young Earth cooled enough such that water vapor (perhaps originating from impacts by icy comets) condensed and collected in the ocean basins As water collected, it dissolved minerals within the rocks After only 20 million years of rain, the oceans were born!

Why study oceanography? ~80% of all Americans live within 1 hour of an ocean or Great Lake 100% of all Long Islanders live within 1 hour of the Atlantic Ocean (and that assumes a good deal of traffic…) 50% of the world’s population live on a coastline

Why study oceanography? We live on Long ISLAND; The ocean is our backyard!!!

Why study oceanography? Our Earth is a BLUE planet Why blue?

Why study oceanography? More than half of the oxygen we breath is produced in the ocean! http://www.nasa.gov/centers/goddard/images/content/95573main_plankton_satellite.jpg

Why study oceanography? Oceans modulate the Earth’s climate

Why study oceanography? Because it’s the stuff of legends (and nightmares…)

Why study oceanography? So you can understand this on a deeper level http://www.youtube.com/watch?v=hwlZUKv57B4

Why study oceanography?

Why study oceanography? WHY NOT???!!!

Oceanography Oceanography deals with understanding the complex relationships between physics, geology, chemistry and biology Oceanography must also consider the relationships between the land and sea, and within the ocean itself

The History of Oceanography Fortunately for us, explorers and scientists have been studying the oceans for millennia and centuries, respectively 1769 chart of the Gulf Stream by Benjamin Franklin

History of Oceanography In fact, the units of latitude and longitude were developed by Alexandrian (Greek) scholars ~200 years BCE Latitude and longitude are systems of imaginary lines dividing the surface of the Earth Essential for navigation

Latitude and Longitude Latitude lines run parallel to the equator Longitude lines run from pole to pole

The History of Oceanography The most famous (and extensive) study of our ocean was conducted by the British in the 19th century The HMS Challenger literally sailed the seas between 1872-1876 Motivated by economic and military interests Explored nearly every all parts of the world’s ocean Seawater samples, biological samples, depths, sediment composition

The Challenger expedition Voyage track from 1872-1876; remains the longest continuous oceanographic survey

History of Oceanography The Challenger expedition successfully disproved the “Azoic hypothesis” – the belief that no life existed below 550 meters Collection of life in the depths launched the science of marine biology! Today, thousands of marine scientists explore the many facets of oceanography around the globe

Oceanography It is said that we know more about the surface of the moon than we do about our oceans Much of the ocean remains unexplored Hundreds of new species are discovered annually With every new piece of information, we have more to learn and more to build upon

Ahoy ye landlubbers, your journey awaits!