C. Geology of ocean basins
C. Geology of ocean basins
C.1 Coastal dynamics
Nature of science:
Scientists use observed and measured patterns to form explanations and make predictions.
Understandings:
The coastal zone has different definitions
Physical factors that affect the coast zone are the substrate, topography, wind, waves, longshore currents and littoral drift that shift with the seasons
Beaches, barrier islands, sandbars, barrier reefs, fringing reefs, cliffed headlands, estuaries, lagoons, bays, and salt marshes are coastal features
Tide zones describe coasts
Coastlines of the Pacific Rim are affected by tectonic activities
Sediment formation, erosion, transport and deposition are active process of apparently static beaches
Sea waves are refracted toward headlands and away from coves and bays
Waves approaching at an angle produce beach drift
Applications and skills:
Skill: Drawing and annotating a generalized topographic profile of a coastal zone.
C.2 Sediments and oozes
Nature of science:
Looking for patterns, trends and discrepancies
Scientists use classification systems to develop observations leading to generalizations
Understandings:
Terminology that describes sources, composition, and sizes of sediments
Characterize biogenous, lithogenous, hydrogenous and cosmogenous sediments as well as calcareous and siliceous oozes
Rates of accumulation vary
Accumulated sediments and oozes provide a history of the basin
Coastal sediments shift in response to currents, waves and storms seasonally and sporadically
Deep sea core sampling verifies seismic profiling
Commercial importance of neritic and pelagic sediments
Applications and skills:
Skill: examining sediments as to composition
Skill: measuring sediments and apply Wentworth scale
Skill: comparing sand samples from different beaches
C.3 Mining the ocean floor
Nature of science:
Scientists analyse data and look for patterns, trends and discrepancies, attempting to discover relationships and establish causal links.
Understandings:
Seismic profiling and deep-sea core sampling have identified mineral resources worth mining on the ocean floor.
Among the resources identified are oil, natural gas, sulfide deposits, placer deposits of iron, tin, platinum, gold and diamonds
Gravel, shells and sand are mined to build roads
Ocean mining is hazardous and expensive
Applications and skills:
Skill: Examining a seismic profile and/or core sample to find evidence of exploitable resources
Application: Oil pollution in the Gulf of Mexico
Application: the oil spill by the Exxon Valdez in the Gulf of Alaska
C.4 Human activity and marine disasters
Nature of science:
Investigating the relationship between human activities to mitigate marine hazards, has taken the form of trial and error.
Understandings:
There is increasing human development along coastlines including docks, ports, resorts, recreational facilities, growing cities, roads, etc.
Forces of nature that are in conflict with human activity include storm surges, oceanic storms, rising sea level, and littoral drift
Human activity has removed natural coastal features such as dunes, wetlands, mangrove forests, as well stabilizing river deltas and straightening rivers so that the original natural safeguards from ocean hazards have been removed.
Shipping, fishing, mining and travel across oceans have lead to disasters especially during storms.
Building of levees, dikes, jetties, groins, breakwaters, dams and sea walls has had variable success.
Artificial replacement of beach sand is a short term solution.
Applications and skills:
Skill: designing and testing models to explore the effectiveness of a structure to prevent beach erosion, survive an earthquake or a flooding event on a coast.
Application: chart the movement of debris from the Japanese tsunamis of 2011 (shipping accidents or other event) and its arrival on the west coast of North America. Consider the consequences of this information.
C.5 Using science to understand marine catastrophes
Nature of science:
Scientists work to assist with disaster preparedness by creating models to solve problems and improve man's lot.
Understandings:
In coastal communities likely to be affected by tsunamis, procedures are in place to avoid loss of life and property.
Warning systems are in place to predict the arrival time and magnitude of tsunamis yet some areas of the world are under-served by these systems.
Steps to prepare for or limit damage vary from community to community
Disasters are measured, risks analysed, interventions are made
Structures such as sea walls have limits to their effectiveness.
Applications and skills:
Skill: developing testable models to alleviate components of coastal disasters.
Application: Choose a place with tsunami damage and describe the nature of the tsunami event(s), what was done to prepare for the disaster, what relief was provided, and what plans have been made for the future.
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