1 / 13

Forces in the Earth – Seismic Waves!

Forces in the Earth – Seismic Waves!. Physical Science Notes 10/8/2012. Seismic Waves. Seismic Waves. Definition: Seismic waves are vibrations that travel through the Earth after an earthquake occurs at a fault. Examples: Compression waves Transverse waves. Seismic Waves.

amity
Download Presentation

Forces in the Earth – Seismic Waves!

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Forces in the Earth – Seismic Waves! Physical Science Notes 10/8/2012

  2. Seismic Waves • Seismic Waves Definition: Seismic waves are vibrations that travel through the Earth after an earthquake occurs at a fault. • Examples: • Compression waves • Transverse waves

  3. Seismic Waves • Compression Waves Definition: Compression waves are waves through matter that is squeezed and stretched. Example: squeezing together multiple slinky coils and then releasing.

  4. Seismic Waves • Transverse Waves Definition: Transverse waves cause matter to move at right angles to the direction the wave is moving. Example: moving a slinky up and down with your hand.

  5. Focus & Epicenter • Focus • Epicenter Definition: The point in the Earth’s interior where seismic waves originate (below the surface). Seismic waves moves outward in all directions from the focus. Definition: The point on the Earth’s surface directly above the focus.

  6. Surface Waves • Surface Wave Definition: Surface waves travel outward from the epicenter along the Earth's surface much the way ripples travel outward from a stone thrown into a pond.

  7. Classwork – Monday 10/8/2012 Earthquake waves classwork (handout, due at the end of the class period)

  8. Homework DUE 10/9/2012 Part 1: Compare and contrast epicenter and focus IN YOUR OWN WORDS (either in complete sentences or a Venn diagram or a labeled illustration) Part 2: Compare and contrast compression, transverse, and surface waves Study for vocabulary quiz tomorrow!

  9. Tuesday 10/9/2012 Vocab Quiz! (turn in) For each term, please summarize the definition IN YOUR OWN WORDS • Fault (& list the three types) • Seismic Wave (& list the three types) • Epicenter

  10. Compression & Transverse Wave Data • Take out a fresh sheet of graph paper. • Make sure your x & y axis are appropriately labeled (“Distance from focus (km)” on the x-axis and “Time of Arrival (hr: min: sec)” on the y-axis). • Put numbers on the x-axis: start at 250 on the left side of the x-axis and count by 1000s (250, 1250, 2250, 3250, 4250, 5250, 6250, 7250, 8250, 9250, 10250) OR count by 500s • Put numbers on the y-axis: start at 4 hours on the bottom of the y-axis and count a minute for each square.

  11. Conclude & Apply:Answer questions under your graph • Based on your graph, which is faster – a compression wave or a transverse wave? • Do the waves remain the same distance apart as they travel? • Do they grow closer together or farther apart over time? • How could you use your graph to fill in the missing arrival times in the chart? • Use your observations to tell why compression waves are called primary waves and transverse waves are called secondary waves.

More Related