Objectives: GEOLOGY 470: FIELD EXERCISE 1 SPRING 2007-- BASIC SURVEYING AND COMPASS USE 1. Determine pace, eye height, and height for use in rough surveying 2. Learn basic compass skills: reading, setting declination, taking bearings, determining vertical angles, use as a level 3. Learn how to use other simple surveying instruments: hand level, Suunto clinometer 4. Learn how to perform simple profile survey with hand level, tape and surveying rod 6. Learn basic techniques of measuring strike and dip 7. Develop field note-taking and data-collection skills Location: HSU campus Founders Hall - Van Matre Hall vicinity and campus to west and south. 1. Determination of eye height Method 1: Using carpenter s level and surveying rod -- you will need someone to assist you with this. a. Set the surveying rod upright -- hold it vertically 6 in to a foot in front of you, with the rod rotated so that the numbers are nearly parallel to your line of sight and facing outward. b. Stand up straight -- don t slouch. c. Have your assistant take the carpenter s level and hold its top surface next to the side of your face at eye-height. d. Have your assistant level the carpenter s level and read-- to the nearest 0.01 foot --where the top intersects the numbers on the surveying rod. e. Neatly record this as eye height inside the front cover of your notebook. Convert it to meters and enter that also. f. Use the level and surveying rod to determine your top-of-head height and record it inside your notebook front cover as height. Convert to meters and enter that also. Method 2: Using mark on wall and tape -- you will need someone to assist you with this. a. Stand sideways next to a wall. Have someone put a small pencil mark on the wall at your eye height. b. Measure the height of the mark with a tape to the nearest 0.01 ft. 2. Determination of your pace -- Founders Hall hallway Starting at 0 near the north basement door of Founders Hall, I have marked the hallway floor at 100, 200, 300, and 350 ft. You will use this to determine your pace, and to assess its variability. Your pace is not your ordinary walking or ambling-along step, nor is it some extreme, forced step. Instead, it is an attempt to smoothly step out a regular, consistent, comfortable distance with each step. My own surveying pace is slightly longer than my ordinary walking step. I consider it slightly forced -- but it is remarkably consistent. Practice in pacing improves your consistency. a. Set up your notebook for data collection. Starting on a fresh page, put the date at the top of the page. Then put in a header label, like Determination of pace in Founders Hall basement. Then lay out a table similar to that below: Determination of pace in Founders Hall basement distance, ft cumulative no of no of paces in distance in pace length, ft paces increment increment, ft 0 ----- ----- ----- ----- 100 100 200 100 300 100 350 50 300 50 200 100 100 100 0 100 total distance, ft total paces ----- ----- mean pace length, ft 700 ----- ----- Note: when collecting numerical or semi-quantitative data, it is good practice to do it using a table. First, it makes it easy to collect and extract the data, because it s clearly organized. Second, and most important, it reminds you of what data needs to be collected at each site, and thus prevents you from making errors and omissions. The table should be laid out in your notebook before you begin collecting data. b. Starting at the 0 mark at the N end of the Founder Hall corridor, pace evenly and smoothly down the hallway; record the total (i.e., cumulative) number of paces you have taken as you cross the 100, 200, 300, and 350 ft tape marks;
when you reach 350, turn around and count your paces back to the far end. The table will remind you where you need to record your cumulative number of paces. c. Determine the number of paces in each increment by successively subtracting your cumulative values. Divide the number of paces into the increment distance to determine your pace length. Round it to the nearest 0.1 ft. Comparing these numbers will give you an idea of the variability in your pace over short distances. (If you feel there was too much variability in your pace, then do it all over again, until you are satisfied.) d. Determine your mean pace length by dividing the total distance paced (700 ft) by the total number of paces taken (last entry in cumulative no of paces column. Enter this in your table, and also inside the front cover of your notebook. Convert it to meters and enter that as well. 3. Introduction to reading, setting, and use of Brunton compass, hand level, and Suunto clinometer for surveying Return to classroom. We ll go through and briefly practice the following: a. reading of Brunton compass b. setting declination of Brunton compass c. taking bearings with Brunton compass d. taking vertical angles with Brunton compass e. using Brunton compass as a hand level f. adjusting and using a hand level, including reading surveying rod g. using Suunto clinometer to measure vertical angles 4. Field practice: measuring distances, bearings and vertical angles From here on, all the field measurements you make should be neatly and clearly recorded in your notebook. Everything must be labeled well enough that anyone looking at your notebook can figure it out. I suggest that you use table form wherever appropriate. Exercises in and adjacent to Founders Hall: a. Bearing of Founders Hall basement corridor 1. Stand in front of the midpoint of the Founders Hall south basement door. Determine the bearing to the midpoint of the Founders Hall north basement door. 2. Walk up the hallway to a point opposite the stairs. Stand above the middle line in the concrete that runs the length of the hall. Carefully align the compass so that its centerline lies along the floor line, pointing toward the N door. Record this bearing. How much does it differ from that you determined in step 1? Caution: there is metal rebar or pipe under the concrete floor which will affect the compass bearing if you hold the compass close to the floor or lay it on the floor. b. Founders Hall courtyard -- go upstairs to the courtyard door. 1. Vertical angle: Walk through the east courtyard door and stand on the first red concrete band running parallel to the long axis of Founders Hall. You can stand to either side of the door, but be sure you re on the red band. Look west and determine the vertical angle to the topmost point of Kerr Tower. Record this. 2. Bearing: Cross the courtyard to the west door., but don t go through it. Stand along center line of the west door take a bearing to the center line of the east door. Record this. 3. Distance: Pace the distance from the west door to the east door. Record your paces and convert it to feet. c. Length of the Redwood Bowl grandstand back -- pacing along Laurel Ave: Start at the north end of the concrete back of the grandstand where it abuts Laurel Ave (the road next to Founders Hall). Pace to the south end. Record the number of paces, and then convert it into the length in feet. We will later tape the distance and compare it with our estimates.
Exercises in and adjacent to Van Matre Hall: d. Bearings and vertical angles taken from the Van Matre loading dock: Near the northeast corner of the loading dock is a small brass benchmark. Stand over (or very near) to the benchmark. 1. Bearing: Determine the bearing to the stadium lightpole at the SW end of the grandstand (see sketch below). 2. Vertical angle: Determine the vertical angle (slope angle) to the platform just below the lights on this lightpole. 3. Bearing: Determine the bearing to the stadium lightpole at the NE end of the grandstand (see sketch below). 4. Vertical angle: Determine the vertical angle (slope angle) to the platform just below the lights on this lightpole. Redwood Bowl grandstand NE stadium lights VMH loading dock not to scale SW stadium lights e. Bearings and vertical angles taken from the top of the stairway west of Van Matre Hall. Stand next to the concrete post immediately south east of the top of the stairs that lead downhill just west of Van Matre Hall. concrete post stairs down Van Matre Hall not to scale 1. Bearing: Determine the bearing to the stack of the pulp mill on the Samoa Peninsula in the distance. 2. Bearing: Determine the bearing to the top center of the Student Services Building skylight. 3. Bearing: Determine the bearing to the campus flagpole near the Library. 4: Vertical angle: Determine the vertical angle down to the topmost point of the western new campus gateway
5. Field practice: surveying a slope profile above Redwood Bowl with tape, hand level, and surveying rod. Reference: surveying handout The field site is on the hillslope above Redwood Bowl, next to the lightpost opposite the east basement door of Founders Hall. Two tapes will be stretched from the top of the slope next to the street to the pavement at the slope base. This will allows two teams to work at a time. The northern tape is Tape 1, the southern one is Tape 2. Use as your reference benchmark (BM1) the top of the flagged nail I ve driven into the asphalt near the lightpost. Let its elevation be 150.00 ft. a. You will need to divide into groups of two. Each group will have a hand level and a surveying rod. Choose one notebook in which to record the data. b. Start the survey notes on a fresh page. At the top of the page give it a title indicating where and along what tape you re running the survey (for example, Slope profile along Tape 1 above Redwood Bowl E of Founders Hall east door, or something similarly descriptive). Put down the names of both individuals involved in the survey, and indicate who is on the level, and who on the rod. When you change off, indicate that at the appropriate point. c. Before you start, lay out a table for the survey data. I would like you to take elevations every 5 ft along the tape, and wherever there is a major break in slope. Your table should look something like this: Tape BS, ft HI, ft FS, ft Elev, ft Notes distance, ft --- BS to BM1 (flagged nail); BM 1 elev is 150.00 ft 0 d. Your first shot should be a backsight (BS) to the top of the nail (BM1) to establish your initial instrument height (HI), i.e., your eye elevation. The rod person will set the rod on the nail, and the instrument person will read it to the nearest 0.01 ft if possible. Once the instrument person has taken that shot, they can t move until it s time to move the instrument because you can t read the rod. Note: the instrument person must stand upright without slouching or stooping when they shoot the rod. If you bend or stoop, you change the instrument height! b. Your second shot should be a foresight to 0.00 on the tape. Enter this in the FS column. Then shoot foresights at 5-ft intervals on the tape until the rod gets too far away to read accurately (i.e., to the nearest 0.05 ft) or it becomes clear that the top of the rod will be below you. When this becomes the case, you will need to move your instrument position to a point lower on the slope. c. When you need to move the instrument (i.e., yourself), let the rod person know. Take a careful foresight on the rod, then tell the rod person to stay put. They must not shift the rod from its position. d. Move downslope to a position where you will be shooting on the lower part of the rod, preferably in the lowest foot or so. Now take a backsight on the rod to determine your new eye elevation. Be sure you enter this backsight in the BS column. e. The rod person can now move downslope and you can resume taking foresights until you reach the pavement. Your last shot should be on the pavement right at the bottom of the slope. Don t move the rod from this last point. f. I would like you to close the survey by surveying back up the tape to the top. In doing this, I want you to change off who s on the rod and instrument. g. The new instrument person must start by taking a backsight to the last rod position. Then start taking foresights uphill. You will more rapidly run out of rod, so you will probably have to do several instrument moves. Remember, each time you (instrument person) move your position, you must take a backsight to a point of known elevation. Be sure you enter these in the BS column. Your best strategy is to move as far uphill as you can while still being able to read the rod to sufficient accuracy. This will minimize the number of backsights and instrument moves. h. Your final shot must be a foresight back to BM1. i. Calculate your elevations. Ideally your final shot back to BM1 should yield an elevation very close to the BM elevation of 150.00. The difference between that and your surveyed elevation is your error of closure. j. At home, use the strategy described in the handout to compute the horizontal (map) distances to each point, and plot up the slope profiles (down and back), using vertical and horizontal scales of 1 in = 10 ft.
6. Strike and dip measurement practice in Founders Hall Reference: read p 34-39 in Compton. We will discuss strike & dip and trend & plunge in class and look at strategies for measuring them. For today s exercises, start on a fresh page in your notebook. Label it with the date at the top. I have arranged six planar pieces of Styrofoam, foam coreboard, or particle board in positions in the classroom or the hallway. Each has a number taped to it. In your notebook make a small table like the one below, and then determine the strike and dip of each numbered surface. Be sure you don t disturb the position and orientation of the pieces! surface number 1 2 3 4 5 6 Founders Hall Strike and Dip Exercise strike dip (angle and general direction) 7. Field practice: measurement of strike & dip, trend & plunge, and heights a. For this exercise, you have been supplied with a base map of the campus. You will be locating all the outdoor items that you measure on it. Before you go out, 1) determine the N direction on the map, and place a north-arrow in the margin of the map; and 2) determine the scale of the map. You may have to measure distances to do this. b. In this exercise, you will take the strike and dip of various planar surfaces -- mostly roofs -- and the trend and plunge of some linear features on campus, and estimate the heights of several objects. Again, I would like you to arrange your data in the form of a table. I suggest a layout below. Any additional notes you take should be keyed to the feature number. c. Locate the positions of the measured outdoor features on the accompanying basemap of the campus as carefully as you can, and then indicate the position on the map with a dot or small cross, and put the feature number next to it. feature (give number and describe) 1. strike & dip of lower banister of center stair 2. trend & plunge of upper banister of center stair 3. trend & plunge of stair handrail W of Founders etc. 11. strike & dip of grandstand roof etc Measure the following things: Measurement of planes, lineations, and heights on campus planes lines heights strike dip (angle trend plunge (describe and (angle and estimation general general method in direction) direction) notes) 1. Founders Hall: strike and dip of the surface of the surface lower banister (flat surface) of the center stair. Caution -- if you lay compass on the wood, metal beneath may affect reading. 2. Go up the stairs one flight: measure trend & plunge of the upper banister (flat surface) of the center stair (consider it as a line, not a plane) Caution -- if you lay compass on the wood, metal beneath may affect reading. 3. Go across the courtyard and out the front door of Founders Hall. Walk to the stairs. Measure the trend and plunge of the center handrail of the stairs leading W from Founders Hall. Caution: rail will affect compass reading if compass is held close above it! 4. Go over to the handicap walkway in front of Founders. Determine the strike & dip of the walkway surface near lightpole 84. 5. Stand at the base of the entire flight of steps in front of Founders Hall. Mark this location on your map with an asterisk *. 6. Walk west from the quad down to the flagpole near Siemens Hall. Estimate the height of the flagpole. Use whatever method you like, but describe in your notebook how you did it and show your calculations. 7. Go to the information kiosk on the east side of the Library. Determine the slope angle of the roof of the kiosk. Enter it in your table under dip -- you only need to put the angle down. 8. Determine the strike and dip of the library porch roof. 9. Walk southward to the sign displaying the name Arthur S. Gist Hall. Determine the strike and dip of the northfacing roof.
Lithologic description 1: Walk south down B Street past the Student Services Building to Harry Griffith Hall. At the junction with 17th cross over to the east side of B and continue south along it until you reach the concrete stairway that leads up to the Campus Center for Appropriate Technology. (There is a prominent sign next to this stairway.) From this point walk south along B street approximately 100 ft. You will find a good exposure of the bedrock making up the hill in the cut along this stretch of sidewalk. Make a sketch of this outcrop, describe the rock, and try to identify it. Pages 27-34 in Compton give you ideas about what you should be doing. 10. Walk back up Laurel Drive (the road that leads up to Founders Hall). Determine the maximum slope angle (i.e., steepest slope) of the road, using whatever technique you consider appropriate. Describe in your notebook how you did it and any necessary calculations. Enter the slope in your table under dip -- you only need to put the angle down. 11. Continue up the road until you come to the Redwood Bowl grandstand. Determine the strike and dip of the grandstand roof. Note: metal in the grandstand walls and the fence along the roof can strongly affect your compass readings if you re not careful. 12. Proceed to the southeast corner of Founders Hall. Determine the strike and dip of the east wall of Founders in this location. Do this by getting your eye into the plane of the wall. Don t put the compass against the wall; rebar in the wall will affect the compass direction. 13. Walk behind Founders Hall until you are next to the first parking space on the south. Estimate the height of the back wall (don t include roof) of Founders in the vicinity of the copper downspout. Use whatever method you like, but describe in your notebook how you did it and show your calculations. YOU RE DONE WITH THE FIELD EXERCISES! All that s left now is the office work. -- calculating elevations, plotting up the cross-sections, putting strikes and dips on the map.
WHAT YOU WILL NEED TO TURN IN TO ME Due date: no later than 5 PM, Monday, Feb. 5. Put in my mailbox in department office or slide under my door. Please be sure all materials are labeled with your name and firmly clipped together. A good strategy is to put them in a folder of a manila or plastic envelope. 1. A clear, readable (i.e., dark enough) photocopy of all your field notes and calculations 2. A neatly plotted and labeled profile of the hillslope you surveyed E of Founders Hall. Plot it on arithmetic graph paper using vertical and horizontal scales of 1 in = 10 ft. Horizontal and vertical axes should be shown on the plot and labeled with elevation or distance as appropriate. (Reference: surveying handout.) The map title should indicate a) which tape line you surveyed, b) who your partner was, and c) the location and date. On a separate piece of paper, include a neat table of your field measurements, and the calculated elevations and horizontal distances. Note: if you want to plot the graph using a computer, that s OK, but you must use a graphing application (such as KaleidaGraph or a GIS or drafting program) which allows you to control the scales so you can get 1 = 10 ft. Excel is NOT adequate for this. 3. Your annotated campus basemap, showing all measurement locations. At its proper location on your map plot the strike and dip or trend and plunge of each outdoor surface or lineation that you measured, using the proper geological symbol. 4. Please fill in the tables or blanks on the attached sheet. This will allow me to rapidly scan your measurements without having to dredge them individually out of your notebook, which can take a long time.
Geology 470 Field Exercise 1 -- Measurement Summary Name: Part 4 a1 a2 b1 b2 FH main corridor bearing FH corridor floor line bearing description FH courtyard vertical angle to Kerr Tower top FH courtyard bearing from W door to E door centerline measurement value b3 FH courtyard distance from W to E door feet c length of grandstand wall feet d1 d2 d3 d4 e1 e2 e3 e4 VMH dock bearing to S stadium lights VMH dock vertical angle to S stadium lights VMH dock bearing to N stadium lights VMH dock vertical angle to N stadium lights VMH stairs bearing to pulp mill stack VMH stairs bearing to center top SBS skylight VMH stairs bearing to campus flagpole VMH stairs vertical angle to top W campus gateway What is the angle between the long axis of Founders Hall (a1) and its cross-axis (b2)? Give the answers below to the nearest whole foot. Part 5 What is the height of the hillslope you surveyed? feet Compare your elevations at 0 on the tape from your downhill and uphill surveys. By how much do these elevations differ? Part 6 Elevation difference: feet (to nearest 0.05 ft) surface number 1 2 3 4 5 6 Founders Hall Strike and Dip Exercise strike dip (angle and general direction)
Part 7 What is the scale of the basemap? 1 in = feet (round to nearest whole foot) feature (give number and describe) 1. strike & dip of lower banister of center stair 2. trend & plunge of upper banister of center stair 3. trend & plunge of stair handrail W of Founders 4. strike & dip of handicap walkway 6. height of flagpole 7. slope angle of kiosk roof 8. strike & dip of library porch roof 9. strike & dip of N-facing Gist Hall roof 10. Laurel Dr maximum slope angle 11. Strike & dip of grandstand roof 12. Strike & dip of Founders E wall at S end 13. Height of back wall of Founders Measurement of planes, lineations, and heights on campus planes lines heights strike dip (angle trend plunge (describe and (angle and estimation general general method in direction) direction) notes) Lithologic description of outcrop:
HSU Basemap for Part 7
Section of Arcata North Quad enlarged 4X