ES REGENTS LAB REVIEW. - Know how to find the p-wave and s-wave arrival times on a seismogram

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1 Name: ES REGENTS LAB REVIEW Station #1: Locating an Earthquake Epicenter - Know how to find the p-wave and s-wave arrival times on a seismogram P S - Know how to calculate the difference in p- and s-wave arrival times s-wave arrival time p-wave arrival time (hr:min:sec) (hr:min:sec) Time Difference:, Epicenter Distance = - Know how to find the DISTANCE TO EPICENTER using the Earthquake P-wave and S-wave Travel Time Graph on pg. 11 of your ESRT Step 1- Use the edge of a piece of scrap paper and line it up vertically along the y-axis (this is the axis is titled Travel Time ) of the graph. Step 2- Mark where 0 minutes is on the edge of your scrap paper. Then, mark the time you calculated for the difference in p- and s- wave arrival times. Step 3- Slide your scrap paper up along the P and S curves that are drawn on the graph. Keeping the edge of your scrap paper vertical, continue to slide your scrap paper until the marks you made match up with the P and S curves.

2 Step 4- Once your marks match up with the P and S curves, draw a line going straight down along the edge of your scarp paper until you reach the x-axis (this axis is titled Distance to Epicenter and the units are in thousands of kilometers). Read the number that your line hits. This is the distance to epicenter from that seismograph station. Step 5- Use a drawing compass and the scale on the map provided, move the slider on your drawing compass until it matches the distance to epicenter on the map s scale. Then, draw a circle (*make sure your pencil is in the correct location on your drawing compass) around the corresponding seismograph station on the map. Step 6- Remember, the location of the epicenter is the point where the 3 circles meet (or intersect), or in the area where they come closest to intersecting. Station #2: Identifying a Rock and Mineral Rock I.D.- 1) IGNEOUS ROCKS (will either have inter-grown crystals, a glassy texture, or a vesicular texture- this is from escaping gases during cooling) a) Types of Textures for Igneous Rocks - Fine, Coarse, or Very Coarse grained - Vesicular (gas pockets from cooling lava) - Glassy These are close-up views of the IGNEOUS rocks pegmatite and granite. Notice how both of these igneous rocks have INTERGROWN CRYSTALS! The crystals grew together and became inter-locked as the magma cooled and solidified. Pegmatite Granite

3 2) METAMORPHIC ROCKS (will either have foliations and/or banding, or will look granular if its non-foliated) a) Types of Textures for Metamorphic Rocks - Foliated - Banding (looks like stripes of minerals in the rock) - Non-foliated (granular) Two examples of METAMORPHIC rocks that show BANDING and FOLIATION of mineral crystals Gneiss and Schist 3) SEDIMENTARY ROCKS (will sometimes contain fossils, like seashells and/or pieces of corals. They are also made up of sediments that are compacted and cemented together, like clay, silt, sand, and pebbles) a) Types of Textures for Sedimentary Rocks - Clastic (made up of broken pieces of other rocks- clay, silt, sand, pebbles, etc.) - Bioclastic (contains fossils- made up of pieces of things that were once living) - Crystalline Contains fossils of seashells and corals Made up of various sizes of rounded sediments that have been compacted & cemented together Made up of various sizes of angular sediments that have been compacted & cemented together Made up of sandsized sediments. Sometimes the sand grains are arranged in different colored layers Made up of clay-sized sediments. This is a very plain looking rock- the sediments are too small to see with your bare eyes.

4 Mineral I.D.- Remember the observable properties of minerals: 1) LUSTER: Metallic (reflects light like a metal) or Nonmetallic (reflects light like anything other than a metal) Luster. 2) CLEAVAGE vs. FRACTURE: Cleavage: Does the broken piece of your mineral have relatively flat surfaces that are at particular angles to each other, such as a cube shape? If so, the mineral has Cleavage. Examples of minerals that have cleavage: Fracture: If the mineral has an irregular breakage pattern and no pattern seems to exist in its crystal shape, then the mineral is said to have fracture. 3) HARDNESS: Can you scratch a piece of glass with the mineral? If so, does that mean the mineral is harder or softer than glass? 4) STREAK: When you rub the mineral on a streak plate, is a colored powder left behind on the plate? If so, the mineral does produce a streak.

5 Station #3: Drawing an Ellipse and Calculating its Eccentricity = Focus #1 = Focus #2 d d = distance between foci L L = length of major axis Eccentricity (e) = distance between foci (d) length of major axis (L) Note: Refer to pg. 15 of your ESRT to study the Solar System Data table. Know how to read the eccentricities for each of the planets elliptical orbits. *Eccentricity does not have units & know how to round it to the nearest thousandth! If you calculate an eccentricity of.2, what is the answer going to be when rounded to the nearest thousandth?