School of Geography and Environmental Sciences

EGM310 Intro to GIS and Remote Sensing Underwater Remote Sensing Handbook: Weeks 5-8

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Contents

01 02 03

Introduction 3

Lectures 4

Practicals 5-20

04

Assignment Cable route selection 9

Appendices

A1

Marking scheme 18

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01. Introduction URS delivery Dr Rory Quinn Room G272 School of Geography and Environmental Sciences RJ.Quinn@ulster.ac.uk Aims 1. To examine the principles and methodology of underwater acoustics as applied to seafloor surveying and exploration; 2. To undertake the integration and interpretation of seafloor data; 3. To demonstrate a range of industrial and academic applications of underwater acoustics, and 4. To develop a range of key skills including problem solving, presentation and communication appropriate to this area. Learning outcomes On successful completion of this module component you should be able to: 1. Understand the basic theoretical concepts behind underwater acoustics; 2. Understand some of the techniques for the acquisition, processing and interpretation of seabed acoustic data, and 3. Successfully integrate a diverse set of marine geological and geophysical data for the solution of a basic academic/industrial problem.

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02. Lectures Slides are available for download at the dropbox link: https://www.dropbox.com/sh/62jofmiee5rxynz/AACV5F9arUFRaQrTwV060n21a?dl=0 No. Title 1. Introduction to module and assignment 2. Principles of underwater acoustics - part 1 3. Principles of underwater acoustics - part 2 4. Bathymetric survey techniques 5. Backscatter data 6. Archaeological applications of underwater remote sensing 7. Geoscience applications of underwater remote sensing 8. Biological applications of underwater remote sensing

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03. Practicals Practical sessions are in IT Laboratory G095. ArcMap is used each week and you will need a minimum of 4 GB storage on a device with real-time read-write access (OneDrive is unsuitable). Bring the storage device with you each week. The practical sessions are designed to develop your GIS skills, acoustic data interpretation skills, and to aid you in the completion of assignment 2: a submarine cable route selection. The material covered in these sessions contributes directly to assignment 2 – attendance at all practical sessions is therefore essential. Relevant data are available for download at the dropbox link: https://www.dropbox.com/sh/il6p1rl9if287nr/AADd0M4uRWZn29qq1X_yHSzca?dl=0 Weeks 5 and 7: Surnames A to L Weeks 6 and 8: Surnames M to Z Practical Title

1. MBES bathymetric data (Weeks 5 and 6) 2. MBES backscatter data (Weeks 7 and 8)

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Practical 1 MBES bathymetric data Introduction These practical sessions are designed to provide you with the skills necessary to complete the associated URS assignment. These practical classes draw on the GIS skills you developed in the first part of the module. The URS practical sessions are designed to equip you with the skills and confidence to interpret and render bathymetric and backscatter data derived from multibeam echosounder (MBES) surveys. During these sessions, you will also build the skeleton of the ArcGIS project you will use as the basis for your assignment. The interpretation of MBES bathymetric data can be approached from many different perspectives. In this practical session, we will concentrate on rendering and interpreting these data from geological, geomorphological, archaeological and anthropogenic perspectives. Therefore, the interpretative skills you learn in these practicals are directly applicable to the URS assignment. Aim To gain confidence in interpreting high-resolution bathymetric data derived from multi-beam echo-sounder surveys and to start building your ArcGIS project for the underwater remote sensing assignment. Learning outcomes By the end of this practical you should:

1. Have developed the basic skills to interpret high-resolution bathymetric data for geological, geomorphological and archaeological applications;

2. Know how to generate shaded relief bathymetric models.

Introduction to the MBES data set To address the need for high-resolution bathymetric data off the north coast of Ireland, the Joint Irish Bathymetric Survey (JIBS) was instigated as a partnership between the Maritime and Coastguard Agency (MCA) and the Marine Institute (MI), funded under the INTERREG IIIA Programme (€2,133,508). The JIBS project commenced on 10 April 2007 and was completed in September 2008, providing:

1. full-coverage multi-beam bathymetry data within the 3 nautical mile coastal strip from Fanad Head (Co. Donegal) to Rathlin Island (Co. Antrim), and

2. ground-truthed, geo-coded backscatter data for the same area.

You will use these bathymetric and backscatter data for the URS assignment.

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Exercise 1: Download and extract the data The data for the URS assignment is available for download at the dropbox link above. This ZIP file contains numerous files, of which the important data files are: mbes_2m_d.img: 2m resolution multi-beam bathymetry (raster data) UKHO_29Nclip.shp: UKHO shipwreck database (shape file, vector data) British Isles.shp: British Isles coastline (shape file, vector data) 1. Create a new folder on your external hard drive (HD) where you will store the data for the practical classes and assignment. I suggest you name this folder with a name that makes sense – e.g. EGM310data indicating the module code and module the component. 2. Download the file zip to the newly created folder on your external hard drive (HD). 3. Extract the contents of the zip file to the folder. You now have most of the data required to complete the URS assignment over the next four weeks. To complete the project, you will need to derive a series of additional products from these data sets and the backscatter data in the next practical. Over the next four weeks, you will use these data in the practical sessions and to complete the assignment. You therefore need to bring the HD with you to all sessions. Exercise 2: Loading and rendering mbes bathymetry data 1. Start ArcMap. If an initial dialog box appears, choose to start using ArcMap with a new empty map. 2. Before you do anything else, save this empty map space as an MXD or Map Package file. It is important that you save this file to the same folder on the HD that you created in Exercise 1. This ArcMap project file will become the basis for your assignment. 3. Now add the three files mbes_2m_d.img, British Isles.shp and UKHO_29Nclip.shp to your project by selecting the Add Data icon on the menu bar. The UKHO_29Nclip.shp layer is the shipwreck database of know shipwrecks in the area as identified by the UK Hydrographic Office. One of the limitations of this database is that it does not contain information on wrecks that pre-date the 17th century. 4. For the remainder of this practical session, we will concentrate on the bathymetric and shipwreck data. Therefore, turn off the backscatter layer by deselecting it in the Table of Contents frame. 5. By default the raster layer representing the bathymetry appear in grey scale. To aid interpretation of these data, you will now change the colour scale of the bathymetric data. Right click mbes_2m_d > Properties > Symbology. At the left side, click on stretched. On the right side change the Colour Ramp to a rainbow colour-scale (cold colours representing deep values, warm colours representing shallow values). Can you see how using colour palettes to render the bathymetry can aid interpretation?

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6. We will now artificially illuminate the offshore landscape (i.e. create a virtual sun) to further aid interpretation. To illuminate the bathymetry, go to ArcToolbox (red toolbox icon in the menu at the top of the screen). Select Spatial Analyst Tools > Surface > Hillshade. When the dialogue box opens, choose mbes_2m_d.img as the input raster and leave the Azimuth and Altitude at the default values. An azimuth value of 315 with an altitude value of 45 means you are going to illuminate the offshore landscape with a sun placed at 315° (in the northwest) at an angle of 45° off the horizon. Select OK – it will take a few minutes to generate the hillshade surface. Once created, it should look like the screen capture below.

7. Now, we want to combine both of these renderings of the offshore landscape into one final rendering of the offshore landscape. To do this, we put the hillshade surface behind the colour-coded bathymetry and make the colour-coded bathymetry semi-transparent to allow the illumination to show through. First of all, drag the illumination layer below the colour bathymetry layer in the Table of Contents. Now double-click the colour-coded bathymetry layer, go to the Display tab and change Transparency to 40%. The map should now look something like this:

8. You should now have an artificially-illuminated digital elevation model (DEM) representing offshore bathymetry for your assignment. This map should become the main decision-making tool for your cable route. 9. Now, we are going to look at the shipwreck database and use it to try and identify shipwreck sites from the MBES data. The first step is to activate the shipwreck database UKHO_29Nclip.shp in

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the Table of Contents if it is not already active. You can change the symbols used to plot these data if you wish by double clicking the layer and changing the symbol type, size and colour. 10. Now, get familiar with these data – the only way to do this is to engage with the data. Start by spending 10-15 minutes zooming in and looking at the data.

• Where are the deepest areas in your study area? Where are the shallow areas? • What features can you see on the seafloor? Can you identify anything unusual? • Using the UKHO data, zoom in to specific shipwreck sites and see if you can image and identify

these sites in the MBES data. Is there good correlation between the UKHO database and the features imaged in the MBES data?

Exercise 3: Interpreting mbes data We will now spend some time looking at various geological, geomorphological and archaeological features on the seafloor. The Stow et al. (2009) bedform-velocity matrix will be used in this exercise. Exercise 4: slope maps and analysis 1. Create a slope map from the bathymetric DEM (mbes_2m_d.img) using the Slope tool (this is in ArcToolbox under Spatial Analyst Tools > Surface). Use the DEGREE option for the Output measurement. 2. By default the raster layer representing the slope appears in grey scale. To aid interpretation of these data, you will now change the colour scale of the slope data. Right click mbes_2m_d > Properties > Symbology. At the left side, click on stretched. On the right side change the Colour Ramp to a rainbow colour-scale (cold colours representing shallow gradients, warm colours representing steep gradients). Your slope map should resemble the screendump below:

Can you see how using colour palettes to render the slope map aids interpretation? 3. Spend a few minutes examining where the steep and shallow areas are located. How do these areas relate to the trends in bathymetry? 4. By selecting the Go to XY icon in the tool bar, examine and interpret the features at the following co-ordinates (it may help to switch on and off the illuminated bathymetric layer to aid your interpretation): Go to: 676160 6123500

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(a) What are these features? (b) Describe the features in terms of their slopes, wavelengths and amplitudes. (c) How many classes of features do you interpret? (d) Classify the features using the Stow et al. (2009) scheme used above.

Go to: 679556 6128027

(a) What is this feature? It might help to turn on the shipwreck layer to aid identification. (b) How do the slopes relate to the actual feature? (c) What are the dimensions of this feature?

Go to: 680369 6124764

(a) What is this feature? It might help to turn on the shipwreck layer to aid identification. (b) How do the slopes relate to the actual feature? How many individual components can you

identify? (c) What are the dimensions of this feature?

Go to: 669123 6129474

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(a) What do you think is happening here in terms of hydrodynamic and sedimentary processes? (b) Now quantify the feature in terms of dimensions, depths and slopes. (c) What implications does this type of feature have for your proposed development?

4. Do not forget to save your ArcGIS project as it develops. EXERCISE 5: Create a slope map containing slopes exceeding 40o only One of the rules by which you will select your cable route is that you are to avoid slopes exceeding 40o. The output from this exercise will result in a map layer that will aid your decision-making. 1. In the slope surface created above, you can see a range of slope values have been classified. While this is useful it is still difficult to identify certain areas. For instance, identifying slopes greater than 40o is difficult. 2. Click on Spatial Analyst Tools in ArcToolbox and select Map Algebra and select Raster Calculator. 3. In the form that appears, double click the slope layer you created (called something like Slope_img1), select the operator >= (greater than or equal to) and type 40. Also make sure that the Output Raster is in an appropriate folder with a sensible name. Once done, click OK. Now wait patiently for the slope map to appear. 4. In the new raster that appears the 0 represents all areas that have a slope of less than 40o. The 1 represents all areas with a slope of 40o or greater. Make the 0 clear (no colour) and make the 1 red. 5. Where are the areas of slope exceeding 40o concentrated? What implication does this have for your route selection?

STEP 3 Create an aspect map from the 1m mbes bathymetric data

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Exercise 6: digitizing routes and generating buffers Now you are going to complete a trial-run of digitizing a cable route. Rather than digitizing an exact route now, you are going to digitize a trial route the following shipwrecks - from HMS Drake in Church Bay through Lugano west of Church Bay to Templemore in Ballycastle Bay. Note that, for obvious reasons, this should NOT be your final chosen cable route. 1. Go to ArcCatalog and create a new shapefile named test_cable in your working directory. You must create this shapefile before you populate it with data. Type the name of the file (test_cable) and select Polyline from the Feature Type. 2. Now we need to tell the software what Co-ordinate System we want the cable route to be digitized in. We are using Universal Transverse Mercator (UTM) Zone 29N (N for north). By default the software tells us it will use an ‘Unknown Coordinate System) as we haven’t told it anything different. Tell it now that you want to use UTM Zone 29N by Edit > Projected Coordinate System > UTM > WGS 1984 > Northern Hemisphere > WGS 1984 Complex UTM Zone 29N. Select OK and OK again. A layer named ‘test_cable’ should now appear in your Table of Contents (ToC). To explain….the Universal Transverse Mercator coordinate system was developed by the United States Army Corps of Engineers in the 1940s. The system, based on an ellipsoidal model of Earth, divides the Earth into sixty zones, each a six-degree band of longitude, and uses a secant transverse Mercator projection in each zone. For spatial mapping, the primary advantage of the UTM system over the latitude-longitude (geodetic grid) system is that the UTM system is metric, so one unit equates to 1m. However, the latitude-longitude system is simpler and more universal, and is what is always used behind the scenes in the global positioning system (GPS), computer systems and GIS software.

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3. You now have a layer that you can populate with the trial-run of your cable route. To switch on the appropriate toolbar go to Customize > Toolbars > Editor. 4. Editor > Start Editing When the dialogue box opens select ‘test_cable’ and OK. Next select the Create Features the icon in the extreme right of the Editor toolbar. Select ‘test_cable’ in the Create Features box and then select Line in the Construction Tools. You have now informed the software you want to add a polyline to the test_cable shapefile. 5. You are now ready to digitize your trial cable route. You can select nodes along your route by a single-click of the left mouse button. To tell the software you have reached the final node (in this case the wreck of Templemore in Ballycastle Bay), double-click the left mouse button. Editor > Start Editing You should now have a route digitized resembling the screen dump below.

6. Now, you will buffer the cable route using a 50m buffer as defined in the assignment requirements. Geoprocessing > Buffer. In the dialogue box select test_cable as the Input Feature and enter 50 (for the 50m buffer) into and Linear unit field. Ensure the unit selected is metres. Select OK and wait. Your buffered route should look something like the screen dump below.

7. Now repeat steps 1 to 6, creating a new trial cable route by digitizing and buffering a line from the north side of Rathlin Island to Sheep Island (the ‘blank’ area located off the north coast in the western portion of the study area). You should now have the skills and confidence to tackle the bathymetric mapping elements of the assignment.

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Practical 2 MBES backscatter data Aim of practical To gain confidence in interpreting backscatter data derived from multi-beam echo-sounder surveys, to continue developing your ArcGIS project for the URS assignment and to export maps from ArcMap. Learning outcomes By the end of this practical you should:

1. have developed the basic skills to interpret backscatter data; 2. know how to generate backscatter mosaics in ArcMap; 3. subjectively and objectively segment backscatter mosaics; 4. know how to export maps from ArcMap for inclusion in your assignment.

Exercise 1: Download and extract the data The data for Practical 2 is available for download at the dropbox link above. This ZIP file contains numerous files, of which the important data file is: mbes_2m_bs.img: 2m resolution multi-beam backscatter (raster data) 1. Download the file zip to your working folder (the one you created last week) on your external hard drive (HD). 2. Extract the contents of the zip file to the folder. You now have all of the data required to complete the URS. Exercise 2: Segmenting backscatter data – a subjective approach 1. Load the backscatter data (mbes_2m_bs.img) if not already loaded. It automatically loads as a greyscale raster. 2. Change the colour palette so that high backscatter values are black and low backscatter values are displayed as white. It should look like this:

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3. Note that the areas with data holes (or data gaps) are where the data is of poor quality and so was not used to generate this backscatter mosaic. 4. By selecting the Go to XY icon and changing the map scale: Go to: 676380 6129975 at a scale of 1:14,000 This brings you to a portion of the seafloor in Church Bay which should look like this:

(a) How many distinct acoustic units can you recognise here (e.g. 2, 3 or 4)? (b) How would you describe each of these units in terms of their backscatter signature (high

backscatter, medium backscatter, low backscatter, low-medium backscatter etc.)? (c) Can you spot the wreck(s) in the data? (d) Now toggle on and off the bathymetric data – can you see the advantage of having the

backscatter data in addition to bathymetric data to aid seafloor mapping?

5. The results of a grab sample exercise in the area are listed in Table 1, can you see think of how you could use the combined backscatter and grab sample data to derive a geological map of the seafloor for this site? How dot he substrate types relate to the backscatter signatures recorded above? Think about grain size and roughness. Easting Northing Sediment type 676007 6130900 Fine sand 677104 6129808 Fine sand 676218 6130063 Sand 676878 6130834 Sandy gravel 674970 6130597 Gravelly sand

Table 1: Results of grab sample exercise conducted in Churh Bay, Rathlin Island. Exercise 3: Segmenting backscatter data – an objective approach

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One of the big issues with segmenting/mapping the backscatter data using the approach in exercise 1 is that that it is based very much on subjective interpretation of the backscatter data. As scientist, we should always aim for an objective approach to mapping. One way to achieve objective segmentation of backscatter data is to use multivariate analysis to categorize the backscatter data. The goal of such classification is to assign each cell in a study area to a defined class or category. Two types of classification are possible in ArcGIS: supervised and unsupervised. In an unsupervised classification, you do not know what features are actually at any specified location (you can establish this at a later stage when ground-truthing the data to generate data such as that presented in Table 1), but you want to aggregate each of the locations into one of a specified number of groups or clusters. What determines to which class or cluster each location will be assigned is dependent on the multivariate statistics that are calculated on the input backscatter raster. Each cluster is statistically separate from the other clusters based on the values for each layer of each cell within the clusters. 1. In the ArcToolbox, go to Spatial Analyst Tools > Multivariate > Iso Cluster Unsupervised Classification. 2. Select the backscatter layer as the input raster layer and change the number of classes to 3. Select OK. I recommend 3 classes as we have previously collected data in the area to ‘supervise’ the classification and 3 is a representative number of classes. 3. Wait until the new raster layer is rendered (it will take some time) – this will be the results of the unsupervised (objective) segmentation of the backscatter data. Change the colours of each class (class 1 to yellow, class 2 to blue and class 3 to green). Now the area around Church Bay should look like this classified map:

4. Zoom to the hull extent of this layer and you will see that the entire backscatter mosaic has been objectively classified using this scheme, and should look like this:

The yellows correspond to fine sand, and the blues and greens correspond to mixes of gravel and coarse sand.

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Exercise 4: Exploring common signatures in the backscatter data You will now re-visit each of the sites you looked at in practical 2 – this time examining the backscatter signature of the sites you looked at in the bathymetric data previously. 1. By selecting the Go to XY icon in the tool bar, examine and interpret the features at the following co-ordinates. It may help to switch on and off the illuminated bathymetric layer to aid your interpretation and compare it to the signatures you recorded in the previous practical: Go to: 676160 6123500 Go to: 679556 6128027 Go to: 680369 6124764 Exercise 5: Creating and exporting maps for the assignment Once you have created your map, you have a number of choices for exporting it. I find the most effective format is to export as a PNG file. PNG is a versatile raster format that can be displayed in web browsers and inserted into other documents. It supports 24-bit color and uses a lossless compression. For maps, PNG is often the best raster format, since the lossless compression keeps text and line work legible by preventing the compression artifacts that can occur in JPEG format. PNG files also have the ability to define a transparent color; part of the image can be displayed as transparent in a web browser, allowing backgrounds, images, or colors to show through. Additionally, PNGs exported from the data view in ArcMap can be generated with an accompanying world file for use as georeferenced raster data. In this exercise, you will use the map export option to create a series of practice maps which will prepare you for exporting maps for you assignment. Map 1: Exporting a single layer The first map you will produce is a bathymetric map with all of the necessary map elements. 1. In the Data View, switch on your bathymetry and hillshade layers. 2. Switch to Layout View and you should have a screen that looks like this:

3. Now add the additional map elements: north arrow, scale bar, and legend using the Insert option from the toolbar. 4. Now add a grid/graticule to the map (right click the map and select Properties) and edit your map until it looks like the one below. Note – when you create a legend and want to edit the legend,

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the easiest way to do this is to convert the legend to a graphic and ungroup it to edit specific elements. This is done by right-clicking the legend and ungrouping. 5. Export the map as a 300dpi PNG file. It should look like this:

Map 2: Exporting multiple layers 1. Now add context to your map by adding satellite imagery of the terrestrial component of the study area. To do this, switch back to Data View and go to File > Add Data > Add Basemap. Select Bing Maps Aerial and choose Add. Wait until image renders. Now play about with the map (zoom in and out) to see examine the terrestrial and coastal environments. Of particular interest will be Church Bay on Rathlin Island and Ballycastle where the underwater cable is to make landfall:

6. Now, export a new map containing the new satellite imagery layer – it should look something like this:

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Including maps and figures in your report All maps and figures in your report should be numbered in order of appearance and should include detailed figure captions – of sufficient detail to stand alone from the main text. An example is provided below.

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Figure 1 Bathymetric map of the study area off the north coast of Ireland. Bathymetric data, at 1 m resolution, is derived from multi-beam echo-sounder surveys as part of the JIBS project.

Final remarks You should now have developed all of the skills necessary to complete the URS assignment for EGM310.

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04. Assignment Optimum submarine cable route selection Deadline Surnames A to L: Sunday 20 November 2016, 23.59, Turnitin Deadline Surnames M to Z: Sunday 27 November 2016, 23.59, Turnitin Scenario You are an independent consultancy, employed by the Northern Ireland Environment Agency (NIEA), to recommend a low-impact route for a submarine cable from Rathlin Island to Ballycastle. As part of the Government’s commitment to renewable energies, a proposed wind farm is to be located on Rathlin Island. The power-scheme is designed to feed electricity to towns in County Antrim. The first supply town on the route is Ballycastle, where the cable makes landfall. The NIEA are concerned that the cable route should have minimum impact on the natural and cultural environments, in line with EU policy. Your consultancy company is therefore tasked with selecting and justifying a suitable marine cable route (from Church Bay on Rathlin Island to Ballycastle) on the basis of the spatial integration and interpretation of existing marine remote sensing data sets. All relevant data sets will be distributed and introduced and discussed in the practical sessions. You are expected to build your own GIS project from these data during the practical sessions and use this as a decision-making tool. All the relevant data sets are projected in UTM Zone 29N. It is therefore essential that you attend and actively participate in all practical sessions. Group Work You can either complete this assignment alone or in a group of up to 3 people maximum - you are responsible for picking and managing your own groups. When submitting the assignment, ensure you include a cover sheet on the front-page of the report that clearly lists members of the group. Guidelines All GIS-derived maps and figures in the report should be professionally produced, clearly structured and contain accurate scale bars, graticules, keys, north arrows etc.. Marks will be deducted for omission of these elements. Figures (and tables) should be numbered in order of appearance and should be accompanied by detailed figure captions – of sufficient detail that the figure and caption can stand alone from the main text. The report should be a maximum of 1500 words. This word count does not include figure captions or references. Marks will be deducted for excessive content. Given that a sub-sea cable will be installed on the seafloor between Church Bay on Rathlin Island and Ballycastle on the north coast of Ireland, the report should clearly outline and justify your chosen cable route using the following guidelines:

1. Installation of the cable will involve trenching to a maximum depth of 2m and post-installation backfilling of the trench.

2. The route must avoid all shipwreck sites, as much bedrock as possible, slopes exceeding 40

degrees and mobile substrates exceeding mean spring flows of 50cm/s.

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3. The proposed route, with a 50m buffer, should be clearly illustrated on a map using the bathymetric and/or backscatter data for context.

4. It is up to you to decide what maps, figures, text and numbers you think are appropriate to

include in the report. Remember – you are dealing with quantitative spatial data, so please quantify as much as possible in the report.

The report should comprise the following sections: 1. Introduction 2. Methodology 3. Results 4. Discussion and conclusions 5. References

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05. Recommended reading Lurton, X., 2010, An introduction to Underwater Acoustics: Principles and Applications (2nd Edition), Berlin; London: Springer-Praxis. (UU Library Shelfmark QC242.2.L87 2010) Plets, R, Quinn, R, Forsythe, W, Westley, K, Bell, T, Benetti, S, McGrath, F and Robinson, R (2011) Using Multibeam Echo-Sounder Data to Identify Shipwreck Sites: archaeological assessment of the Joint Irish Bathymetric Survey data. International Journal of Nautical Archaeology, 40(1): 87-98. (http://dx.doi.org/10.1111/j.1095-9270.2010.00271.x) Stow, D, Hernandez-Molina, FJ, Llave, E, Sayago-Gil, M, Rio, VDD and Branson, A, 2009, Bedform-velocity matrix: the estimation of bottom current velocity from bedform observations, Geology, 37(4): 327-330. (http://dx.doi.org/10.1130/G25259A.1) Van Landeghem, KJJ., Wheeler, AJ, Mitchell, NC and Sutton, G, 2009, Variations in sediment wave dimensions across the tidally dominated Irish Sea, NW Europe, Marine Geology, 263: 108-119. (http://dx.doi.org/10.1016/j.margeo.2009.04.003) Westley, K, Quinn, R, Forsythe, W, Plets, R, Bell, T, Benetti, S, McGrath, F and Robinson, R (2011) Mapping Submerged Landscapes Using Multibeam Bathymetric Data: a case study from the north coast of Ireland. International Journal of Nautical Archaeology, 40(1): 99-112. (http://dx.doi.org/10.1111/j.1095-9270.2010.00272.x)

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A1. Assignment marking scheme

Module code Student name(s) Module title Coordinator/marker Assignment Module Contribution

Maps (20%) Maps professionally drafted, clear, with accurate legends, north arrows, scales, units and labels

Maps Maps are unprofessional and missing some/all map elements.

Bathymetric data analysis (20%) Bathymetric data is used to accurately derive secondary products (e.g. hillshade, slope maps) and to classify bedforms and infer bottom currents.

Bathymetric data analysis Routine use of bathymetric data only, with little or no derivatives or analysis.

Backscatter data analysis (20%) Isocluster analysis of backscatter data completed and accurate substrate map derived.

Backscatter data analysis No isocluster analysis and no substrate map produced.

Wreck data analysis (10%) UKHO sites are plotted and individual wreck sites and processes are interpreted from MBES bathymetric and backscatter data.

Wreck data analysis Wreck analysis limited to plotting of UKHO sites.

Cable route selection and justification (10%) Cable route meets criteria and is well-justified in terms of data interpretation and logistics.

Cable route selection and justification Cable route ignores criteria and /or is not justified.

Presentation (10%) Outstanding presentation, logically structured, correct spelling and grammar. Figures are correctly numbered and contain detailed captions

Report presentation Poor presentation and structure, spelling and grammatical errors. Figures are not numbered and/or do not contain detailed captions.

Referencing (10%) Outstanding referencing and bibliography. Extensive evidence of integrating appropriate supplementary sources.

Referencing Little or no referencing and bibliography. Little or no evidence of reading.

Feedback

Marked by Mark *

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* Marks are provisional until confirmed by the Board of Examiners

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