Introduction

This compact disk (CD) is an interactive atlas of data from the eastern Section of Juan de Fuca Strait (48°00' - 48°30' N; 122°10' - 123°45' W). This project has been a collaborative effort between staff of the Geological Survey of Canada (GSC) and the United States Geological Survey (USGS), supported by the USGS National Earthquake Hazard Reduction Plan (NEHRP) and GSC and USGS A-base. There are several types of information presented within this Atlas. The background geology and tectonic setting is established with maps of bedrock, surficial relief, earthquake seismicity, and regional aeromagnetic, gravity and tomographic data. New data for the project largely come from recent seismic reflection surveys and shallow piston cores. The track information and core sites from these expeditions form several map sheets. Results from compilation and interpretation of these data form the remaining data sheets.

Data are presented in two forms: raster images presented on html pages and vector data and images presented through themes in the ESRI* GIS program, ArcExplorer 1.1, which can be installed from this CD on Windows 95/98 or Windows NT 4.0. The html pages are best viewed with Netscape Navigator 4.0 (or higher) or Internet Explorer 4.0 (or higher). The html pages present the maps in raster image form with numerous links to text and figures. This introduction page and the map pages open up within the bottom right frame. Following each map is a description of the associated ArcExplorer themes and their relevant fields and a discussion of the data presented, including links to examples of the data, with interpretations.

Introduction Panel and Setup

On insertion of the CD, a front introduction panel should have opened, with the title and buttons to launch the applications. If this did not occur, then it is likely the CD-ROM player is not configured to permit "autorun". Either change the configuration or launch the atlas by clicking on the intro.exe in the folder \Atlas. After ArcExplorer is installed, reintroduce the CD or restart the computer.

The button to launch the ArcExplorer project (<GIS>) with all the map sheets relevant to this atlas will not appear on the front introduction panel unless ArcExplorer has been installed on your computer. ArcExplorer requires 7.2 MB of free space on the hard drive. There is a button (Install ArcExplorer) on the start-up window (the intro panel) of this CD to run the install file, aeclient.exe. Before installing ArcExplorer, uninstall any previous versions of ArcExplorer that may be on your computer. If Windows NT is running on your computer please note:
1) Service Pack 3 must be installed in order to run ArcExplorer 1.1. If it is not installed, ArcExplorer 1.0 can be downloaded from ESRI and used without Service Pack 3.
2) Installation of ArcExplorer on computers running Windows NT requires administrator privileges.

ArcExplorer

ArcExplorer is Geographical Information System software which presents map data. This overview of ArcExplorer discusses aspects of ArcExplorer that are relevant to this atlas. If you wish to know more about how ArcExplorer works, you may access the Help Menu by pressing F1 or by going to the ESRI web site, http://www.esri.com/.

Data may be presented in one or both of two forms: vector data and raster image data. Each vector data set is presented in the form of a theme, which is presented as a layer. These layers are transparent, with data from other layers showing through. Themes are listed in a column on the left side of the ArcExplorer window. The first theme in the list is the top layer and the last theme is the bottom layer. The order of the themes may be changed by dragging the theme boxes up or down in the list, or by right clicking on the theme and selecting "move to". Visibility of the themes is controlled by clicking on the white square to the left of the theme name. When the box has a check mark in it, the theme is visible. Data may be presented in one of three shape types: point, line or polygon. During this introduction, when the phrase 'data point' is used, it refers to a data point, data line or data polygon. Clicking on the theme name or symbol results in a box around the theme and this indicates that the theme is 'active'. Only one theme can be active at any time and the active theme can be queried. The following is a table of the themes that are available in this atlas:

Theme Description
BOUNDARY Lines of vector data which define the perimeters of the region.
COASTLINE Lines of vector data which define the coastlines of land bodies.
LATITUDE/LONGITUDE Lines of vector data which show the latitude and longitude graticules of the region.
UTM GRID Lines of vector data which show the Universal Transverse Mercator Zone 10 (Longitude reference: -123).
LAND The landmass surrounding the eastern Juan de Fuca Strait is filled with a solid colour
BATHYMETRY CONTOURS Lines of vector data which show bathymetry contours.
BATHYMETRIC RELIEF A sun-illuminated shaded relief map of BATHYMETRY of the Strait.
BATHYMETRY (Image) A colour raster image that represents bathymetry data.
BATHBAR (Image) A colour raster image that provides a legend for the BATHYMETRY (Image) theme.
MAPPED FAULTS Location of faults as presented in existing literature, prior to this investigation
REGIONAL GEOLOGY Polygons of vector data which present the geologic setting for the region.
GRAVITY CONTOURS Vector contour lines of raw free-air gravity data.
GRAVRAW (Image) Colour raster image of raw free-air gravity anomaly data.
GRAVRBAR (Image) A colour scale bar for the RAW GRAVITY (Image) theme.

GRAVPROC (Image)

Colour raster image of processed free-air gravity anomaly data.
GRAVPBAR (Image) A colour scale bar for the PROCESSED GRAVITY (Image) theme.
MAGNETICS CONTOURS Vector contour lines of aeromagnetic anomalies.
MAGRAW (Image) A colour raster image of sun-illuminated aeromagnetic data.
MAGRWBAR (Image) A colour scale bar for the RAW MAGNETIC (MAGRAW) theme.
MAGPROC (Image) A colour raster image of processed sun-illuminated aeromagnetic data.
MAGPRBAR (Image) A colour scale bar for the PROCESSED MAGNETIC (MAGPROC) theme.
TOMO1KM A colour raster image of TOMOGRAPHIC results (acoustic velocity) at a 1 km depth slice.
TOMO3KM A colour raster image of TOMOGRAPHIC results (acoustic velocity) at a 3 km depth slice.
TOMO5KM A colour raster image of TOMOGRAPHIC results (acoustic velocity) at a 5 km depth slice.
TOMOBAR A colour scale bar for the TOMOGRAPHY themes.
SEISMICITY: 0-5 km RECORDED EARTHQUAKES 1981-1999 for 0-5 km depth within the crust
SEISMICITY: 5-10km RECORDED EARTHQUAKES 1981-1999 for 5-10 km depth within the crust
SEISMICITY: ALL RECORDED EARTHQUAKES 1981-1999 for all crustal events
CORE SITES PGC96006 Points of vector data which show the location of cores taken during the Geological Survey of Canada's PGC96006 research cruise.
CORE SITES PGC97007 Points of vector data which show the location of cores taken during the Geological Survey of Canada's PGC97007 research cruise.
CORE SITES 1999 Points of vector data which show the location of cores taken in 1999
TRACKLINES PGC96006 Lines of vector data which show the tracklines run during the Geological Survey of Canada's PGC96006 research cruise.
TRACKLINES PGC97007 Lines of vector data which show the tracklines run during the Geological Survey of Canada's PGC97007 research cruise.
SHIPS TRACKLINES Lines of vector data which show the tracklines run during the Seismic Hazard Investigations in Puget Sound (SHIPS) research cruise (PGC98002).
USGS TRACKLINES Lines of vector data which show the tracklines run during the 1995 United States Geological Survey's research cruise.
INDUSTRY (1) TRACKLINES Lines of vector data representing industry tracklines.
INDUSTRY (2) TRACKLINES Lines of vector data representing industry tracklines.
SANDWAVES Polygons of vector data showing locations of SAND WAVES and DUNES.
SURFICIAL GEOLOGY Polygons of vector data showing the SURFICIAL GEOLOGIC UNITS of the seafloor
DEPTH TO QUATERNARY Contours of the mapped DEPTH to the BASE of the QUATERNARY section
QDEPTH (image) Colour raster image of the DEPTH to the BASE of the QUATERNARY.
QDEPTBAR (image) Colour bar scale for the QDEPTH map
QUATERNARY THICKNESS Contours of the mapped THICKNESS of the QUATERNARY section
QTHICK (image) Colour raster image of the THICKNESS of the QUATERNARY section
QTHICBAR (image) Colour bar scale for the QTHICK map
STRUCTURE POINTS

Vector point data showing the location of mapped structures from seismic reflection data. Points represent Quaternary and pre-Quaternary FAULTS and FOLDS.

SEDIMENT DEFORMATION FEATURES Vector point data showing the location of mapped SEDIMENT DEFORMATION features from seismic reflection data.
STRUCTURE Lines of vector data, showing the trends of FAULTS and FOLDS as interpreted from the seismic reflection and magnetic anomaly data. Data are broken into pre-Quaternary and Quaternary faults and folds.

The Map Tips tool Map Tips Toolis available when a theme is activated. The Map Tips Window lists data fields that are available for a particular theme. Select the field of interest, click OK, and when the cursor moves over a data point of the active theme, the value of the selected field is shown (Figure 1).

Figure 1

Figure 1. Map Tips Tool Example.
Active Theme: TRACKLINES PGC96006
Selected Field: LINE

 

Selecting the Theme Properties tool Theme Propertiesor double clicking on a theme, brings up a box in which you can change the colour, style, size of symbol used. There is also the opportunity to change the symbol classification. In order to use this data, it will not be necessary to change the symbol or its classification. Changing the symbol classification, however, provides an alternative method for viewing values for data points. Choosing the 'No Overlapping Labels' classification option brings up a window in which the user can choose the field to display values for, the label font, the label size and label placement (Figure 2). Please note that, in this case, it is not necessary for the theme to be active for the labels to be displayed and any number of themes may utilize this symbol classification.

Figure 2

Figure 2. Changing symbol classification example.
Theme: TRACKLINES PGC96006

Symbol classification: No overlapping labels
Selected Field: LINE
Font: MS Sans Serif; size 8
Label Placement: Place above

 

To facilitate navigation around the map there are a variety of tools: Zoom In Zoom In, Zoom Out Zoom Out, Zoom to Active Theme Zoom to Active Theme, Zoom to Full Extent Zoom to Full Extent, Zoom to Previous Extent Previous Extentand Pan Pan. For the Zoom In and Zoom Out tools, the cursor may be clicked on a region to zoom in or out. Also, the cursor may be clicked and dragged over a rectangular area for a more specific view. Zoom to Active Theme changes the view to the extent of the theme that is presently active. Zoom to Full Extent allows one to view the combined extent of all the themes. Zoom to Previous Extent changes the map view to the previous view. Pan is used in a click and drag manner to move around the map. There is a Direction Tool Direction which allows for panning in a north, south, east or west direction. A drop down menu allows for direction choice and then clicking on the map pans the view in the chosen direction.

The Find tool Find brings up a window which allows the user to find a specific value. First, type in the value to find (case-sensitive text). Next, select the search type: any part of field, whole field or start of field. Finally, select the theme or themes to be search. Clicking on the field selects (highlights) it and clicking on a selected field deselects it. Holding down the Shift button and clicking on consecutive fields allows more than one theme to be selected. In order to choose themes that are not in consecutive order, hold down the Ctrl button and click on the themes. To start the search, press the Find button. All the fields in each selected Theme are searched for the particular value. Search results are displayed on a table in the Find Window. In order to locate a particular result, click on it within the table of results. Then the option is given to highlight, pan to and/or zoom to the selected result.

There is also a Query Builder Query. Using the Query Builder allows one to exactly define the subset of data to highlight. Queries can combine data from different fields of the active theme. The Query Window allows you to build the query string by clicking on field(s), operators (<,=,>,>=, <>, <=, and, or, like) and the values of selected fields. The string may also be typed in but the query is precise and case sensitive so it is advisable to click on the buttons in order to avoid errors and obtain the correct results. If the string is typed in, % is used as a wildcard character. The option of which field to display the results in or of showing all the attributes of a given point is presented. After the string is complete and the display field is chosen, click on the Execute button. The results are given in a table within the Query Window. Results may be selected individually and then highlight, pan and/or zoom may be selected. Entire results may be examined by pressing the Highlight Results button and/or the Zoom to Results button. A statistical analysis may also be performed on the values of a theme. Clicking on the Statistics button displays a window in which a field can be selected to perform the analysis on. The analysis results in values for count, maximum, mean, minimum, standard deviation and sum. Within the window, there is also the option of choosing to perform the analysis on the query results and not the entire set of data within the field. Query results may be saved by clicking on the Save button Save, or cleared by clicking the Clear button Clear.

In order to determine all the attributes of a particular point, choose the Identify Tool Identify. The Identify Tool may be used with the active theme only. When a feature is clicked, a window appears which displays the X and Y coordinates (given in UTM coordinates), the data values for each field, and the shape type of the feature as well as the theme that is presently active.

Some of the ArcExplorer data sets are presented as raster images. These themes are presented as a whole unit rather than a group of point, lines or polygons and are identified by (Image) after the theme title. Raster images are opaque, not transparent like the theme layers are. For most of the raster images there is an accompanying legend bar.

As an additional resource, ArcExplorer has extensive help files. While you are in ArcExplorer, these may be accessed by pressing F1 or by clicking on Help in the Menu Bar. ESRI also has a web site http://www.esri.com/ from which further ArcExplorer and GIs information can be obtained.
*ESRI and the ESRI Logo are licensed trademarks of Environmental Systems Research Institute, Inc.

Overall Citation
Mosher, D.C. and Johnson, S.Y. (eds.), Rathwell, G.J., Kung, R.B., and Rhea, S.B. (compilers), 2000. Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931.

Specific Citations for each map sheet:

Relief
Mosher, D.C., Kung, R., and Hewitt, A.T., 2000. Modern surface morphology of the eastern Juan de Fuca Strait, in: Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B., and Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931

Regional Geology
Johnson, S.Y., and Mosher, D.C., 2000. The eastern Juan de Fuca Strait - regional geology map, in: Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B., and Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931

Seismicity
Mulder, T., and Rogers, G., 2000. Recorded seismicity of the eastern Juan de Fuca Strait, in: Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B., and Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931

Potential Field Geophysics (Gravity and Magnetics)
Blakely, R., and Lowe, C., 2000. Aeromagnetic anomalies of the eastern Juan de Fuca Strait region,
in: Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B., and Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931

Lowe, C. and Blakely, R., 2000. Free-air and Bouguer gravity anomalies of the eastern Juan de Fuca Strait region, in: Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B., and Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931

Tomography
Brocher, T., Parsons, T., Fisher, M.A., Tréhu, A.M., Spence, G.D., and the SHIPS Working Group, 2000. Three-dimensional tomography in the eastern Juan de Fuca Strait: preliminary results from SHIPS, the 1998 Seismic Hazards Investigation in Puget Sound, in: Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B., and Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931

Data Control (Cruise Tracks and Core Positions)
Mosher, D.C., 2000. Data Report for CCGS John P. Tully PGC96006 October 15-October 31, 1996, in: Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B., and Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931

Mosher, D.C., 2000. Data Report for CCGS John P. Tully PGC97007- Leg I August 5-16, 1997, in: Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B., and Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931

Johnson, S.Y., Dadisman, S.V., Childs, J.R., and Rhea, S.R., 2000.
Data Report for Cruise G3-95-PS, June, 1995, in: Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B., and Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931

Mosher, D.C., Mi, Y., Hyndman, R.D., Fisher, M., and SHIPS Scientific Party
, 2000. SHIPS (Seismic Hazard Investigations in Puget Sound) Multichannel Seismic Reflection Tracklines, in: Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B., and Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931

Johnson, S.Y., Dadisman, S.V., and Rhea, S.B., 2000. Industry Seismic Reflection Tracklines, in: Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B., and Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931

Quaternary geology (Bathymetry, Surficial Geology and Quaternary Depth and Thickness)
Mosher, D.C., Kung, R.B., and Hewitt, A.T., 2000. Seafloor morphology of the eastern Juan de Fuca Strait,
in: Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B., and Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931

Hewitt, A.T., and Mosher, D.C., 2000. Surficial geology of the eastern Juan de Fuca Strait,
in: Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B., and Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931

Johnson, S.Y., Rhea, S.B., Dadisman, S.V., and Mosher, D.C., 2000. Depth to the base-of-Quaternary in the eastern Juan de Fuca Strait region,
in: Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B., And Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931

Johnson, S.Y., Rhea, S.B., Dadisman, S.V., and Mosher, D.C., 2000. Thickness of Quaternary strata in the eastern Juan de Fuca Strait region, in: Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B., and Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931

Neotectonics
Mosher, D.C., 2000. Distribution of soft-sediment deformation features in the eastern Juan de Fuca Strait, in: Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B., and Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931

Johnson, S.Y., Mosher, D.C., Dadisman, S.V., Childs, J.R., and Rhea, S.B., 2000. Tertiary and Quaternary structures of the eastern Juan de Fuca Strait: point map, in: Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B., and Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931

Johnson, S.Y., Mosher, D.C., Dadisman, S.V., Childs, J.R., and Rhea, S.B., 2000. Tertiary and Quaternary structures of the eastern Juan de Fuca Strait: interpreted map, in: Mosher, D.C. and Johnson, S.Y. (Eds.), Rathwell, G.J., Kung, R.B., and Rhea, S.B. (Compilers), Neotectonics of the eastern Juan de Fuca Strait; a digital geological and geophysical atlas. Geological Survey of Canada Open File Report 3931

Troubleshooting

The map pages do not open up within the bottom right frame of the main page.

Refresh/reload the main page or close and restart your browser.

More than one theme seems to be active in ArcExplorer.

Close ArcExplorer and open it again.

The browser pages are not appearing correctly (overlapping text, etc.)

Maximize the browser window. In the Control Panels of your computer, select Display properties and go to the Settings Section. There is the option to select the Font Size. Select the 'Small Fonts' option.

 

Acknowledgements

This work was supported by the United States Geological Survey, National Earthquake Hazard Reduction Program (NEHRP), through external research grant no. 1434-HQ-96-GR-02725 to David C. Mosher. The work was also supported by Geological Survey of Canada and US Geological Survey A-base funding. A compilation such as this atlas requires the efforts of many individuals. Firstly, the editors would like to thank all of the co-authors and the compilers. Their contributions and efforts make this endeavour and the final product worthwhile. DCM would like to thank G. Rogers for suggesting the need for an investigation into the neotectonics of the eastern Juan de Fuca Strait and R. Currie for tremendous support and sage advice. The support of the staff at the Pacific Geoscience Centre is also greatly appreciated. R. Franklin designed the CD cover and did a significant amount of data digitizing. The efforts of the officers, crew and scientific staff of the survey vessel CCGS John P. Tully, during cruises PGC96006, PGC97007, and PGC98002 are greatly appreciated. In particular, DCM would like to thank Captain John Anderson, skipper on all three cruises, for his skilled seamanship, but also for his great attitude and deep interest in the project. He is truly one of the best skippers with whom DCM has had the pleasure of sailing.

Contact Information
-------------------
Questions, suggestions, and comments regarding this CD-ROM should
be addressed to:

David C. Mosher
Geological Survey of Canada - Atlantic
P.O. Box 1006
Dartmouth, NS
B2Y 4A2

Tel: (902)426-7730
Fax: (902)426-4104
E-mail:dmosher@nrcan.gc.ca
or mosher@agc.bio.ns.ca


Samuel Y. Johnson
United States Geological Survey
P.O. Box 25046, MS 966
Lakewood, CO 80225
1711 Illinois St.
Golden, CO
USA

Tel: (303)-273-8608
E-mail: sjohnson@gldage.cr.usgs.gov