The instruction below to answer the questionsINTRODUCTIONSince the plate tectonic revolution in the late 1960’s, our view of how the world works has changeddrastically Plate tectonics successfully explains how earthquakes, volcanoes and mountain beltsform and how the continents and oceans have evolved with time One of the most useful pieces ofinformation are magnetic anomalies recorded in the ocean floor that allow us to determine rates anddirection of sea floor spreading through time and to reconstruct past plate configurations In this labyou will do several exercises to gain a better understanding of plate motion and ratesPlate ReconstructionsThe evolution of the San Andreas fault system over the last 30 million years is shown belowThe Pacific plate currently is moving past the North American plate at a rate of about 35cm/year
1 During what time (in millions of years) would you expect volcanoes near Los Angeles?
2 Why would there be volcanoes at this time (ie, what would create them)?
3 Should the volcanoes be active today? Why or why not?
4 Using the scale on the map and the rate of plate motion above, determine how long it will
take Los Angeles to reach San Francisco
Please use the instruction below to answer the questions SeismicitySeismicity is simply another way to say earthquakes Areas of high seismisity levels are typically,but not always, coincident with those of recent volcanic eruptions Differences in earthquake depthtend to indicated plate boundary differences Below is a seismicity map of the world, focused on thePacific Plate â also called the ring of fire due to the large occurance of volcanic activity
1 What is the difference in seismic activity between the California coast of the US and thePeruvian / Chilean coasts of South America?
2 What is the reason for this difference? (refer to your notes on plate boundary types)
3 Describe the pattern of earthquake depths that you see along the coast of Chile 4 Why is this pattern occuring?