Topographical maps

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Topographical maps

http://reynolds.asu.edu/topo_gallery/topo_gallery.htm

cliff

Mountain

Complex valley

Earth Quakes

What do you know about earth quakes?

Your Assignment:

• Invent a specific quake and imagine yourself in it.

• Open the template I have sent you on Phy Sci resources.

• You are going to write about your earthquake from three view points; News reporter, scientists, and eyewitness.

Earth Quake Causes

• They occur in Zones that coincide with the edges of the Lithospheric plates. (crust and upper section of the mantle)

• Deformation of the earths crust:– Compression– Tension; stretched– Shear; move opposite directions– Torsion; twisted

Earthquake waves• Focus; the point of origin• Epicenter; on the surface directly above the

focus.

http://cse.ssl.berkeley.edu/lessons/indiv/davis/inprogress/QuakesEng3.html

Earthquake waves

BODY WAVES

• P waves• S waves

P waves

• Primary waves.• The rock vibrates in the same direction the

wave is moving.

S waves

• Shear waves or Secondary waves• Particles move perpendicular to the direction

of wave travel

Surface waves

• Can be like S waves • Like Ocean waves with rolling motion• Cause the most Damage to structures

Types of Faults

• Normal Fault: Tension forces• Reverse fault; Compression forces• Strike slip fault: Shearing forces• animations

Measuring earthquake strength

• Richter Scale and Modified Mercalli Scale• Measured by a seismograph

Richter Scale

• Based on the measurements of amplitude of seismic waves

Modified Mercalli Scale

• Measures the amount of structural and geological damage and earthquake causes or its intensity.

Richter scale

What happens to buildings in an Earth quake?

• They sway from the ground floor up.• Taller buildings are more flexible and sway

more. Shorter buildings shake to pieces.

Seismic Safe Structures

• A structure that is resistant to the vibrations from earthquakes. It will still be standing!!!!!

• The building and foundation need to be built to resist the sideways motion (load). Diagonal bracing.

• Allow the structure to move as a unit and not shake.

• Dampers that can absorb the motion so it is not transferred to the building.

Building material that absorbs motion. Large bearings ( rubber or springs) in the foundation

Make structures that can bend.Strengthening the foundation and securing the

building to the foundation

• Diaphram

• Diaphragms are horizontal resistance elements, generally floors and roofs, that transfer the lateral forces between the vertical resistance elements (shear walls or frames). Basically, a diaphragm acts as a horizontal I-beam. That is, the diaphragm itself acts as the web of the beam and its edges act as flanges. (See figure 1)

http://mceer.buffalo.edu/infoservice/reference_services/basicseqdesign.asp

• Shear wall

Shear walls are vertical walls that are designed to receive lateral forces from diaphragms and transmit them to the ground. The forces in these walls are predominantly shear forces in which the fibers within the wall try to slide past one another.

• Braced Frame

• Moment Resistant Frame

Volcanoes and Earth quakes

Volcanoes

• Molten rock beneath the surface called Magma rises through the crust.

• This forms Lava on the surface.• Form at Subduction Zones both Continental

and Oceanic

Ring of Fire

Types of Volcanoes• Cinder Cone: large fragments of solid

materials

Shield Volcanoes

• Abundant lava flows; broad and flat made up of layers of lava flows.

Composite Volcanoes

• Include pyroclastic materials and lava flows. Usually along Convergent plate boundaries

• Water and silica forced down to mix at the boundary produce an especially viscous magma.

Mount Rainer in WA

The End

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