VOLCANOES. {Singing} I don t know, I don t know, I don t know where I am-a gonna go when the volcano blows!

Transcription

1 Name: Tymesha B, Manny U, Malaika R VOLCANOES {Singing} I don t know, I don t know, I don t know where I am-a gonna go when the volcano blows! --Jimmy Buffett Part 1 Volcanic History of New Jersey Use the Earth Science Reference Tables (ESRT) and NJ Geological Survey resources to answer this first set of questions. (1 pt. ea.) 1. The Palisades formed about 195 m.y.a. as a sill. Explain what this term means: The term sill means an intrusion has entered between the older layers of sedimentary rocks. Only occurs when the foundation is weak or cracked, then those same cracks are filled and given the layer appearance. What evidence proves these rocks formed as a sill? The result of previous magma solidifying, over a million years the overlaying rocks would eventually erode, forming the Palisades Most of the Palisades is diabase. What are the four main minerals in this rock? What is its texture? Four main minerals in the Palisades diabase are plagioclase feldspar, pyroxenes, olivine, and biotite. The texture is described as complicated textures. A textural and chemical difference from the upper and lower parts of the sill, show that crystallized materials were transported from the roof to the floor during solidification of the magma sheet 2. Garret Mountain and the rest of the Watchungs formed about m.y.a. as lava flowed into a shallow lake. What evidence proves this? The evidence that proves this is that the Watchungs has a layered look.

2 The Watchungs are composed of basalt. Compare their minerals and texture with the Palisades. The Palisades has these larger plagioclase crystals, when the Watchungs is composed of fine milled crystals. Basalt is the simple state of diabase is the modified version of basalt. 3. Hook Mountain (3 rd Watching) is largely a vesicular basalt. Explain what this mean. What do the vesicles imply about the origin of Hook Mountain means and how it differs from the basalts on Garret Mountain? The vesicles imply that the origins of Hook mountain was formed when magma was cooled to lava, leaving the lava to harden around gases and let them be preserved. Volcanoes, p Other igneous features in NJ Look at the bedrock geology map on the NJGS website where else are igneous rocks found in NJ? Other igneous rocks in New Jersey can be found in Essex, Union, Warren, and Sussex counties. Bonus Do a web or print search and find out about Laurel Hill (aka, Fraternity Rock), a prominent feature next to the eastern spur of the NJ Turnpike near Exit 15X (Lautenberg Train Station.) Part 2 The Nature of Volcanic Eruptions Use the appropriate chapters in your textbook to answer this set of questions. 1. Explain the difference between lava and magma. (1 pt.) The difference between lava and magma is that magma is molten materials that form deep

3 beneath the surface or as the result of a volcanic eruption; when lava is contained by oxygen and magma is pure and hot contaminated. When magma reaches the surface it is called lava. 2. Make a drawing in the space below to represent the pyroclastic materials of the cone, crater, vent, and magma chamber. (2 pt.)

4 Volcanoes, p The three factors that influence whether a volcano erupts explosively or quietly are listed in the table below. Complete the table to compare how differences in magma composition affect how the formation of pyroclastics. (1/2-pt ea., total 6 pt.) Composition Silica content (felsic or mafic) Viscosity Gas content Tendency to form pyroclastics Basaltic Least (50%) Least Least (1-2%) least Andesitic Intermediate (60%) intermediate Intermediate (3-4%) intermediate Rhyolitic Most (70%) greatest Most (4-6%) greatest 4. Complete the table below to describe basic types of volcanoes and other igneous rock structures. Include at least 3 4 facts about each. (2 pt. ea., 12 pt. total) Type of volcano/igneous feature Shield volcanoes Important Facts Are produced by the accumulation of fluid basaltic lavas. Cinder cones Ejected lava fragments the size of cinders, which harden in the airs build a cinder cone

5 Composite cones Earths most beautiful and potentially dangerous volcanoes are composite cones, or stratovolcanoes. Most are located in a relatively narrow zone that rims the pacific ocean Lava plateaus The greatest volume of volcanic material is extruded from fissules Plutons The structures that result from cooling and Harding of magma Sills and dikes Plutons that form when magma intruded close to the structure Volcanoes, p. 4 Part 3 Volcanoes of the US Use the US Geological Survey Volcano Hazards resources to answer these questions. (1 pt. ea.) 1. Examine the map on the home page.

6 a. Tell where volcanic activity is occurring in mainland North America. The volcanic activity is occurring in Wyoming in mainland North America. b. What volcanoes are active on Hawaii? The volcanoes that are active on Hawaii is Kiloawa, Halem uma u Crater c. Where else are volcanoes active in US Pacific Territories? Volcanoes are also active in California, Oregon, and Washington 2. Click on Activity in the upper bar menu. a. Which volcanoes are on Watch status? Where are they located? The volcanoes that are on watch status is Cleveland volcano and Kilawa volcano b. Which volcanoes are on Advisory status? Where are they located? The volcanoes that are on advisory status is Pagan volcano c. Choose three volcanoes on Normal status where are they located? The three volcanoes that are on normal status is Cascade range, Yellowstone, and Maura Sea

7 Volcanoes, p Click on Hazards in the upper bar menu. a. Select any four of these, and describe below what threats they create for people. (4 pt.) Landslides- the landslide may transform into a lahar and flow down valley more than 100 kilometers from a volcano Lava flows- they destroy everything in their path but move slow enough for people to get out the way. Lahars- large tahars hundreds of meters wide and tens of meters deep can flow several tens of meters per second- much too fast for people to out run Tephra-is fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism

8 b. Describe at least three ways in which people can prepare for volcanic emergencies. (3 pt.) 1. Know beforehand where the active volcanoes are in your area. 2. put together emergency kit 3. have communication devices around