ACE Class Report – Oceanography Part 2
Begin: 2/25/2024
Finish: 5/12/2024
Title: Oceanography 2
Exploring Earth’s Final Wilderness
Instructor: Professor Harold J. Tobin
University of Wisconsin
Why I choose to take this class:
To learn more about the ocean. How human interaction and pollution affects it. Understand how the ocean’s affect on climate, ecology, environment and what can we do to protect it.
What I learned from this class:
How the physics of water controls the ocean:
The dissolved minerals (salt) in the ocean are in a remarkable chemical equilibrium due to vigorous global mixing, which is governed by density differences due to the temperature and salinity. The chemistry of the ocean is the same all over the world, but the concentration or salinity varies. Salinity and temperature determine difference in density that govern the stratification of shallow and deep water in the ocean. Biological processes regulate ocean chemistry; this life on earth controls its own environment.
Waves – Motion in the Ocean:
Ocean waves are generated by the drag of wind blowing over water and can travel as swells thousands of miles from where they are generated: their size and speed are governed by whether they travel through deep or shallow water. Wave size and type is governed by wind, speed, duration and fetch. Normal waves affect only the uppermost levels of the ocean. Waves refract around shallow and deep portions of the near-shore ocean floor, changing direction of size.
Rogue Waves and Tsunami:
Tsunami result from sudden displacement of the ocean floor and overlying water due to an earthquake or landslide. Tsunami have wavelength of hundreds of kilometers and therefore travel according to the rules of shallow-water waves even crossing the deep ocean at ultra high speeds. Rogue waves are single waves that form by constructive interference of 2 or more swells. They can reach heights of 100 feet or more.
Tides in Theory and Practice:
Tides are the result of gravitational attraction of the sun, moon and ocean water. Tides are affected by the amphidromic circulation,and depending on location. Tides can be Diurnal, semidiurnal, or mixed.
Marine Life, Energy and Food Webs:
All life on earth can be divided into primary producers and consumers. Trophic pyramids and food webs are ways to understand the complex feeding and energy relationships among members of a marine community
Tiny Plankton – The Most Abundant Life on Earth:
Floating microscopic plankton, comprising a wide range of both plantlike organisms and animals. Phytoplankton are the green plants of the sea. Zooplankton are the animals, they range from microscopic to giant jellyfish.
Soft-Bodies Life in the Dark, Open Depths:
Beneath the sunlit Euphotic zone, the dark water supports a diverse ecosystem of organism, many of which have no hard parts to their bodies and are virtually transparent. The basis of the Pelagic food web is mainly detritus raining down from surface waters. In the darkness, bioluminescence is an important means of both attracting prey and confusing predators.
Swimming – The Many Fish in The Sea:
Nekton are all the actively swimming organism in the ocean ranging from fish to invertebrates to mammals and birds. Squids, octopus and nautilus are mollusks, which are invertebrates. The most successful Nekton family are the bony fish.
Marine Birds, Reptiles, and Mammals:
Marine mammals -Cetacea (Whales and Dolphins), Sirenia (Manatees) and Carnivora (seals, sea lions and walrus) evolved from land-dwelling mammals. Toothed whales use echolocation to find prey.
Whaling, Fisheries, and Farming the Ocean:
Ocean fisheries are a major source of food and a highly efficient industry, but most species are both overfished to unsustainable levels, necessitating fish farming or aquaculture. Aquaculture is an increasingly important part of the overall fish supply – with its own impacts on the ocean environment.
Where Sea Meets The Land and Why Coast Vary:
The characteristics of coasts are governed by the interplay of erosional and depositional process resulting from sea-level changes, plate tectonics, glacial cycles, and other factors. Erosion-dominated coast exhibit rock cliff, fjords – result from land uplift due to plate tectonic or glacial retreat or drowned river valley that result form rising sea level. Net accumulation and movement of sediment dominates on depositional coasts, producing long beaches and wetlands.
Where Rivers Meet The Sea – Estuaries and Deltas:
Human activity is now extensively modifying the natural deposition and erosion processes in coastlines and combined with gradual sea-level rise, is causing loss of beaches and natural barriers in many areas. Seawalls and other structures designed to protect buildings ironically can make beach erosion worse. Loss of sediment supply and protective vegetation leaves many coastal areas more susceptible to storm damages.
How will this class contribute to my success upon release:
Better understanding of ocean and how the environment is being impacted by humans make me more aware of my duty as a citizen to protect the ocean, its inhabitants and avoid activities that will pollute it. This knowledge will be spread to other communities when I volunteer my services through teaching, tutoring and mentoring.
