SEISMIC WAVE BASICS Finding an Epicenter ESRT TABLES

SEISMIC WAVE BASICS

Finding an Epicenter ESRT TABLES – GRAPH PAGE 11

What is an Epicenter? • A point on the surface of the Earth directly above the focus of the earthquake – where the destruction (buildings / people) occurs. • Focus - The point in the Earth from which earthquake waves originate – where the earthquake begins!

Use the data from the recording stations: • Station A: San Francisco, California P-Wave arrival 3: 02: 20 S-Wave arrival 3: 06: 30 What is the time difference between P and S wave arrivals?

Use the data from the recording stations: • Station B: Denver, Colorado P-Wave arrival 3: 01: 40 S-Wave arrival 3: 05: 00 What is the time difference between P and S wave arrivals?

Use the data from the recording stations: • Station C: Missoula, Montana P-Wave arrival 3: 01: 00 S-Wave arrival 3: 00 What is the time difference between P and S wave arrivals?

Difference in arrival times: San Francisco, CA: 4: 10´ Denver, CO: 3: 20´ Missoula, MT: 2: 00´

TAKE A PIECE OF PAPER, AND MARK OFF THE DIFFERENCE IN ARRIVAL TIME 4: 10 2800 Km

MOVE THE PAPER UNTIL THE TWO TICK MARKS LINE UP WITH THE P AND S CURVES WHEN TICK MARKS LINE UP, GO STRAIGHT DOWN AND READ THE EPICENTER DISTANCE OF 2800 KM

EPICENTER DISTANCES San Francisco, CA: 4: 10 2, 800 km Denver, Co: 2, 000 km Missoula, MT 3: 20 2: 00 1, 100 km

http: //www. eram. k 12. ny. us/education/page/ download. php? fileinfo=Rmlu. ZGlu. Z 0 Vwa. W Nlbn. Rlci 5 zd 2 Y 6 Ojovd 3 d 3 L 3 Nja. G 9 vb. HMvc 2 Mvcm. Vtb 3 Rl. L 2 lt. YWdlcy 9 kb 2 Nt. Z 3 Iv. NDQ 2 Zmls. ZTU 4 Nj. Iuc 3 dm

Recording Board Difference in arrival times: 2, 800 km San Francisco: 41: 0 5, 000 4, 000 3, 000 2, 000 0 1, 000 Line your compass up to the EXACT distance on the scale. Use the metric side (cm) beginning from zero.

1100 km . . 280 0 km 20 00 km

Compare your answer to the historical record Missoula Syracuse X San Francisco Denver