MARINE GIS IN THE EASTERN PACIFIC
Nested Sampling Strategies and a Scientific Information Management Schema for Deepsea Environments

Dawn J. WRIGHT

New opportunities continue to arise for geographical information scientists to venture offshore. One of the most pressing is in the field of ocean floor mapping, where we still know less of our ocean floor than we do of the topography of Venus and Mars (99% of which have been mapped in enough detail to reveal features on the order of 50 m in height). In fact, we have made more progress in the past 20 years mapping the surface of neighboring planets than we have in the past 500 years mapping the ocean floor of our own planet . However, the development in the last 10-20 years of sophisticated technologies for ocean data collection and management hold tremendous potential for mapping and interpreting the ocean environment in unprecedented detail. With the understanding that ocean research is often very costly, yet deemed extremely important by large funding agencies, geographical information scientists now have the opportunity to perform coastal and marine studies that are more quantitative in nature, to formulate and test basic hypotheses about the marine environment, and to collaborate with scientists working in corollary subdisciplines (e.g., geomorphologists, political geographers, computer scientists, nautical chart specialists, etc.), as well as with classically-trained oceanographers. This contribution reviews the newest advances in mapping and management technologies for undersea geographic research (particularly on the ocean floor) and discusses the contributions that geographical information scientists stand to make to a greater understanding of the oceans. Described is a scientific information management schema for the integration of accurately-located, high-resolution topographic, photographic, seismic, chemical, geological, biological and acoustic data from the Endeavour Segment (Northeast (NE) Pacific) into a marine GIS for support of a seafloor observatory program. When complete, the marine GIS will become an essential component of the observatory program by: (1) enabling scientists to integrate several databases into a georeferenced system, where logical queries can be made and spatial relationships assessed between various layers or themes of data; (2) providing a rapid, “unselfish,” and logical way to disseminate knowledge, enabling rapid response to such events as seafloor seismic activity, volcanic eruptions and their ensuing megaplumes; and (3) maximizing the scientific return on the millions of Federal dollars spent by the U.S. National Science Foundation, the National Oceanic and Atmospheric Administration, and other agencies involved in collecting data from throughout the NE Pacific.

KEYWORDS:  Oceans, Regional to Global Mapping, Ocean Floor Mapping, Bathymetry, Seafloor Spreading, Underwater Vehicles, Information Management and Modelling, Marine GIS, Interdisciplinary Science.

INTRODUCTION
Of the many forms of representation that geographers use to characterize the Earth - numerical, statistical, graphical - maps often come to mind as the foundation of geographic inquiry, particularly in the minds of the public [55]. And yet geographers have been largely absent from the push to map the final frontier of the planet: the oceans. Indeed, if one were to define marine or ocean geography as that branch of geography concerned with “location, place, region, and space” [6] on the surface and bottom of the oceans, as well as the distribution of life within the water column then a survey of published literature within recent decades will reveal that this sort of work is not being done by geographers. Indeed, as geography has traditionally embraced both the physical and human sciences and sought to provide a bridge between the two, the study of the oceans beyond the realm of the nearshore has escaped attention. Messerli and Ehlers [35] ably discuss various reasons for this.
Within the past 10 years, as the greater scientific community has seen a dramatic increase in support for research into global Earth systems and the effects of human-induced change, geographers have begun to broaden their focus past traditional boundaries. Ocean geography as it was known in the past is no longer limited to the coast, but is slowly embracing studies of the deep ocean realm, as well as lakes and small seas. Such an embrace may be very costly however, both in research dollars and time spent at previously inaccessible study sites. It will therefore be important for geographers to continue fostering interdisciplinary relationships with classically trained oceanographers and ocean engineers to secure the necessary funding along with a broader sense of community with these scholars, a theme that will be revisited in the paper’s conclusion. Steinberg [50] states that terrestrial geographers may learn much from the study of ocean space. Similarly, classical oceanography (the broad science of physics, biology, chemistry, geology, and geophysics applied to the ocean realm) may glean much from a geographical approach. For example, as will be discussed in a later section entitled “Scientific Discoveries: From Pattern to Process to Protection,” several important scientific questions have arisen from a decidedly geographical approach to interpreting ocean floor data, focusing on geographic information systems (GISs). As Monmonier noted, “what a friend we have in GIS” [37], which has ushered in new ways of analyzing these data, that in turn have facilitated new interpretations. Indeed, research issues endemic to oceanographic applications of GIS, such as the handling of spatial data structures that with the ability to vary their relative positions and values over time, geostatistical interpolation of data sparse in one dimension as compared to the others, volumetric analysis, and the input and management of very large spatial databases will advance the body of knowledge in GIS design and architecture, as well as the body of knowledge in the broader field of geographic information science. 
New opportunities continue to arise for geographers to venture offshore. One of the most pressing is in the realm of mapping the deep ocean floor, where, we have made more progress in the past 20 years mapping the surface of neighboring planets than we have in the past 500 years mapping the abyss of our own planet [29]. However, the development in the last 10-20 years of sophisticated technologies for ocean data collection and management hold tremendous potential for mapping and interpreting the ocean environment in unprecedented detail. What follows is a review of these emerging technologies and how they are being applied to the ocean floor, as well as case studies that illustrate the important role that the coupling of geographic techniques with these technologies can play in linking observed pattern to physical process.
OCEAN MAPPING TECHNOLOGY
When viewed from space, the Earth appears strikingly as a planet of water, with 71% of it surface covered by a fluid envelope averaging 5000 m in depth. This envelope a vast inner space, which, along with the underlying ocean floor, is still only dimly perceived by humans. What can be perceived of the water column and ocean floor must be done mostly with the aid of sound, as sound waves are transmitted both farther and faster through seawater than electromagnetic energy. In order to “see” the ocean floor for instance, sound is essential not only for determining depth to the bottom, but for detecting varying properties of the bottom. Sound reflects back after striking an object on the seafloor and the intensity of this reflection, or backscatter can be used to sense the shape of objects or the character of the bottom (e.g., heavily sedimented and thus non-reflective or glassy with fresh lava flows and thus extremely reflective). Depths are commonly measured by timing the two-way travel time of a sound pulse released from a research vessel, towed instrument, or vehicle. As the speed of sound in seawater varies linearly with temperature, pressure, and salinity, the conversion of travel time to depth must take this into account [24].

Global Scale Via Satellites.  In terrestrial terms, research vessels and their associated instruments and vehicles must travel quite slowly during mapping efforts (anywhere from 1 to 12 knots, or the speed of an average bicycle commuter). In order to map the global ocean floor at this rate it would take approximately 125 years and $5 billion [47, 63] even with the latest acoustic mapping tools described below. Fortunately, satellite determinations of sea surface height can be used to estimate ocean floor topography on small scales (covering the globe in a little over a year at a cost of ~$80 million) (Yulsman 1996), leaving shipboard techniques to tackle the larger scale mapping efforts. Radar altimeters aboard satellites take advantage of the fact that the surface of the ocean bulges outward and inward in a fashion mimicking the topography of the ocean floor because of minute variations in the earth’s gravitational field. Recently declassified data from Geosat, combined with data from the ERS-1 satellite of the European Space Agency, have provided the best detailed view of the ocean floor on a global scale, revealing structures never before seen, particularly in the southern oceans where ships have difficulty in rough weather (Figure 1) [47].

Figure 1. Global map of ocean floor gravity from Geosat and ERS-1 satellite altimetry (public domain data of [47]). Estimates of ocean floor topography may be derived from these data. Prominent among the visible features in the gravity is the Mid-Atlantic Ridge, which appears as a faint seam along the center of the north Atlantic Ocean. The deep trenches of the north and west Pacific, as well as thousands of seamounts, are also visible. Study area described in the article is marked by white rectangle.

Regional Scales Via Ships and Towed Vehicles. While satellite gravity data reveal all discrete ocean floor structures larger than 10 km horizontally and 1 km vertically, operations at sea are still required to detect and interpret structures at a higher resolution. Surveys at this regional scale are carried out with multibeam swath mapping systems that are either mounted to the hull of a research vessel or towed behind the vessel as a vehicle. These systems are termed “multibeam” because their transmitting arrays send out several simultaneous, downward-looking beams of acoustic energy across the track of the vessel, creating a 1-10 km-wide swath of coverage (depending on the water depth). Although limited to vessel speeds of 10-12 knots, these multibeam swath mapping systems rapidly generate high resolution bathymetric maps (i.e., of depths to the ocean floor) over much larger areas of seafloor than their single beam predecessors of the 1950s and ‘60s. One hull-mounted system that is now accepted as a de facto standard within the marine mapping community is Sea Beam, whose 16 beam-array can map ~1200 km2 of seafloor per day at a contour interval of 10-20 m (the coverage of a single-beam system is ~400 km2 per day at a 100-200 m contour interval). The Sea Beam 2000 series was introduced in the early ‘90s with a 121-beam array (Figure 2) that often triples the bathymetric mapping output of the original Sea Beam system [1].

Figure 2. Composite drawing of the various state-of-the art technologies available for ocean floor mapping (after [11]; reprinted by permission of Woods Hole Oceanographic Institution, Deep Submergence). Inset shows the R/V Atlantis, of the Woods Hole Oceanographic Institution. The Atlantis is equipped with a hull-mounted Sea Beam 2100 multibeam swath mapping system for mapping large areas of the ocean floor. Sea Beam 2100 data were used to construct the perspective image at the top right. Detailed near-bottom surveying is possible with the DSL 120 towed vehicle, followed by larger scale visual imaging with the Argo II vehicle. At an even large scale, detailed imaging and sampling are possible with either the Alvin submersible (DSV = Deep Submergence Vehicle) or the Jason ROV (Remotely Operated Vehicle).

Several towed vehicles have been developed to work in combination with hull-mounted systems such as Sea Beam. These vehicles are equipped with long-range, side-looking sonars that measure not only the traveltime but the strength and direction to an ocean floor reflector. So in addition to high-resolution bathymetric maps, these vehicles provide the acoustic equivalent of an aerial photograph of the ocean floor (called sidescan sonar imagery). The vehicles are usually towed in order to shield their sonars from ship noise, as well as propeller and wave turbulence, and to enable their use with more than one research vessel during a field season. Currently the most popular towed vehicles among North American marine scientists are the HMR-1 vehicle of the Hawaii Mapping Research Group, University of Hawaii (towed 150 m below sea surface, 20-30 km swath width), GLORIA II of the U.S. Geological Survey (towed 30-60 m below sea surface, 14-60 km swath width), and DSL 120 of the Deep Submergence Laboratory (DSL), Woods Hole Oceanographic Institution (towed ~75 m above the ocean floor, 300 m swath width; Figure 2). Argo II, also of the DSL, is a towed vehicle primarily for visual imaging (Figure 2). 

Hull-mounted swath mapping systems and towed vehicles have led to some remarkable discoveries, particularly along the mid-ocean ridge, the largest, most striking feature on the planet at a length of 70,000 km throughout all the world’s ocean basins. The mid-ocean ridge comprises 95% of all the plate tectonic boundaries found on Earth, and dominates the volcanic flux of the planet, creating an average of 20 km3 of new oceanic crust annually, which in turn contributes up to 66% of the heat lost from the interior of the Earth [31]. Bathymetric maps produced by swath mapping and towed vehicles, in concert with various geophysical studies, have shown that instead of a continuous rift valley as originally conceived, the ridge consists of segments, each a few kilometers in length and linked end-to-end along the axis of seafloor-spreading. This strongly suggests that processes in the lower crust and upper mantle respond to plate separation in a discontinuous, but systematic way [31]. Many more maps and bottom observations are needed to document the amount of extension along the ridge and to characterize degrees of segmentation.

Local Scales Via Submersibles.  Mapping is of course a fundamental component of ocean floor investigation but must often go hand-in-hand with sample collection of rocks, biota, and sediments from smaller areas on the ocean floor (typically 0.1-1 km2). It is here that the submersible becomes a valuable and necessary element of deepsea investigative capability. The submersible couples not only acoustic, but visual imaging with a system that permits complex and interactive sampling and equipment deployment, usually via powerful and dexterous robotic arms [7]. The fundamental limitation of the vehicle is the human component. As a consequence of needing to provide life support for the occupants, bottom time is limited to an average of 8 hours, no more than 12. The time, however, is well spent as often the scientist returns from a submersible dive with a completely different, hypothesis-altering perspective of the ocean floor [21, 34, 58].

Underwater vehicles with human occupants date back to the 1600’s. However, the first true submersible, so classified because of its maneuverability, was the Trieste which took Jacques Piccard and Donald Walsh to a record-breaking depth of 10,912 m in 1960 [43]. In the wake of Trieste’s success, the number of scientific submersibles grew dramatically, continuing to the present with the Americans, the Japanese, and the French leading the way. The most distinguished and heavily used of U.S. submersibles is Alvin (Figure 2), famous for its 1986 visit to the wreck of the H.M.S. Titanic. [2].  Over the last 30 years Alvin has taken over 8300 observers to the ocean floor during more than 2800 dives over the time span of 18,000 hours underwater [7]. In 1974 Alvin and the now retired French submersible Archimede, dove on the Mid-Atlantic Ridge as part of Project FAMOUS (French-American Mid-Ocean Undersea Study), which helped to confirm the theory of plate tectonics and continental drift. Sea Cliff and Turtle, both of the U.S. Navy, are also in use by the North American scientific community, and the French submersible, Nautile is the distinguished workhorse of the European scientific community.
	
Nested Strategies With Remotely-Operated Vehicles (ROVs).  During the last 25 years of high-resolution exploration of the ocean floor, there have been not only fundamental, exciting scientific discoveries made (see [7, 8, 11, 29, 30] for a fuller description), but also much has been learned about what combination of tools is needed to fully investigate the interdisciplinary scientific questions at hand. For example, a towed vehicle collecting swath bathymetry and side-looking sonar, towed ~100 m off the bottom at a speed of 1.5 knots, may image ~130 km2 of ocean floor per day. A similar platform with camera/video capabilities, towed ~10 m off the bottom at 1 knot would image less than 1 km2 of ocean floor per day. A manned submersible with a bottom time of 6 hours may traverse 1-3 kilometers of ocean floor during a dive or carry out sampling or experimental tasks at a single location. Given these spatial limitations, a nested investigative strategy (analogous to “multistage" in terrestrial remote sensing) is in order: (1) use the high-resolution mapping capability of the towed vehicle to resolve properties of the ocean floor at scale large enough to place the results of a near-bottom investigation into a regional context; (2) deploy a submersible, like a dart aimed at a specific target, to investigate, sample, and characterize a limited number of diagnostic locations with the regional framework defined by the towed vehicle [7]. As effective as this strategy is, it is still limited by the short time scale of the manned submersible investigation. 
	
The last 10-15 years have seen the development of remotely operated vehicles (ROVs) for scientific and industrial applications in shallow coastal waters (less than 1000 m). ROVs have all the characteristics of a towed vehicle with an additional capability to maneuver on a tether for high-resolution investigations and interactive tasks on the bottom. In the last decade ROVs have been aggressively developed for scientific research applications in deep water. A host of engineering problems unique to working at great depths have largely been solved, and the technological innovations pioneered for shallow-water ROVs (e.g., lights, cameras, thrusters, robotics, etc.) have been adapted by their deep-water counterparts. Like the towed vehicles for deep water, these ROVs are powered by a conducting cable to the surface ship and can carry out scientific missions for several days to weeks on the bottom; like submersibles, these ROVs can remain stationary and carry out complex sampling and imaging tasks [7]. On the whole these ROVs, when well navigated, can carry out mapping tasks at a range of scales that are unprecedented both on the ocean floor and up in the water column. The m- to cm-scale sonar and image-based maps that can be produced are beyond the resolution of the hull-mounted and towed systems and are achieved much more effectively than submersibles. The marine science community is just beginning to ascend the ROV “learning curve” in terms of system configuration and implementation, but clearly the ROV represents a significant step function in humankind’s ability to characterize the global abyss [7, 41, 46, 53].

In addition to ROVs, autonomous underwater vehicles (AUVs), which are still largely developmental, hold great potential for future mapping and data collection as they are completely untethered. Elimination of the tether frees the vehicle from the surface vessel, removes the need for large and costly handling gear, and allows for continuous operation up to 1 year. Communication with the vehicle through the water and over such a long time period is still extremely difficult, as is equipping the vehicle with the necessary on-board intelligence to successfully complete all of its tasks without human supervision. Two free-swimming vehicles that have been tested recently for deep-water science missions are the Odyssey II and the Autonomous Benthic Explorer (ABE), both developed at the DSL of WHOI. In 1995 ABE completed its first official science mission by successfully gathering magnetics data and visual imagery from the CoAxial segment of the Juan de Fuca Ridge in the northeast Pacific (Figure 3) [52, 63].

Figure 3. Photograph of Autonomous Benthic Explorer (ABE) being deployed over the side of the R/V Atlantis II during its first official series of scientific missions to the Juan de Fuca Ridge, northeast Pacific, summer of 1995, Atlantis II Cruise 132-12.

ISSUES IN OCEAN SPATIAL DATA MANAGEMENT
The introduction of these sophisticated tools has necessitated the development of reliable data management systems for the various data streams. The cost of acquiring the data alone (seagoing operations run upwards of $25,000 per day) justifies the development of dedicated systems for the management and integration of these data. And there is always the goal of using these systems as an analysis tool to optimize scientific interpretations and facilitate the rethinking or reformulating of hypotheses. As mentioned before with nested surveying strategies, bathymetric data from a swath mapping system located underneath a ship may need to be georeferenced to underwater video images or sidescan sonar data collected from a vehicle towed behind the ship and several meters above the ocean floor, to sample sites, observations, temperature measurements, etc. collected from a submersible or ROV launched away from the ship and operating directly on the ocean floor, to earthquake data obtained from an ocean bottom seismometer anchored on the seafloor. The data produced by these different sensors will invariably have different dimensionalities, resolutions and accuracies. And as transmission rates of up to several Gb per day at sea become more and more commonplace the ability to assess ocean floor data collected at these different scales, in varying formats, and in relation to data from other disciplines has become crucial. Here geography has made a contribution through the introduction of GIS, which fulfills not only the requirement of data integration but of combining or overlaying data of the same dimensionality. This also serves as an efficient means of assessing the quality of data produced by one instrument as compared to another. Geographers have contributed greatly to assessing and solving many problems that apply very much to the ocean environment, including: the management of very large spatial databases [17, 49, 51], uncertainty and error propagation [4, 5, 19, 22], the designation of “core” or “framework” data sets for sharing and archiving [16], and the development of standards for spatial data and metadata, i.e., information about data [10, 40].

The development of appropriate metadata and metadata standards for ocean floor and other types of oceanographic data is an extremely important issue. This is pertinent to oceanography regardless of whether or not the data have been used in a GIS context. The growth in information technology has led to an explosion in the amount of information that is available to researchers in many fields. This is particularly the case in the marine environment where a state-of-the-art "visual presence" (through real-time video or 35-mm photography) may result in the acquisition of data that quickly overcomes the speed at which the data can be interpreted. The paradox is that as the amount of potentially useful and important data grows, it becomes increasingly difficult to know what data exist, where the data are located (particularly when navigating at sea with no “landmarks”), and how the data can or should be accessed. In striving to manage this ever-increasing amount of data and to facilitate their effective and efficient use, metadata becomes an urgent issue. In the U.S., the Federal Geographic Data Committee has funded the first proposals ever to address the issue of standards development for coastal and marine metadata, under the National Spatial Data Infrastructure (NSDI) Cooperative Agreements Program [33]. One of the most ambitious and effective efforts to date in the area of ocean data management and metadata creation is the Statewide Ocean Resource Inventory (SORI) project, funded by the National Oceanic and Atmospheric Administration (NOAA) through the Florida Coastal Management Program. The SORI project aggressively fills gaps in ocean floor and other types of data along the Florida coast, maintains them in a GIS and executes a distribution mechanism via the World Wide Web, with the goal of providing information in a format that can be used by those developing Florida’s ocean policy [18, 56]. As a result of various issues raised by Florida’s Ocean Policy Roundtable, NOAA’s office of Ocean and Coastal Resource Management has formed a partnership with the NOAA Coastal Services Center to advance ocean GIS throughout the South Atlantic region [12, 18]. An ambitious effort on the Gulf Coast of the U.S. is the Water Quality Information System (WaterQUIS) of the University of Alabama, with a goal of characterizing the spatio-temporal dynamics and linkages between various physical, chemical, and biological processes of relevance to water quality conditions and forecasts throughout the Mobile Bay watershed (oak20.geography.ua.edu).

On the west coast of the U.S., and directly related to the ocean mapping technology described previously, is the Vents GIS project, funded by the Vents program of the NOAA Pacific Marine Environmental Laboratory. The Vents GIS focuses on geological, geophysical, chemical, and biological data from the Juan de Fuca seafloor spreading center and is the first major GIS project designed exclusively for deep ocean data and metadata [15, 59]. It integrates data from multiple conventional sensor and sample analysis systems, as well as interpretive information from video and sidescan sonar data analysis. One important component in the effective implementation of the entire data management infrastructure has been the definition of a semantic model that allows users and designers to capture the meaning of the various databases. A semantic data model essentially defines objects, relationships among objects, and properties of objects, thus providing a number of mechanisms for viewing and accessing a database schema at different levels of abstractions [44].  A number of semantic data models have been developed and described in the computer science and information management literature [23, 32, 36, 42, 62]. The successful application of a marine geography database is closely linked to various unique requirements for data acquisition and near real-time analysis, previously considered only by Gritton et al. [20] for undersea data from a single vehicle. Wright [59] considers the requirements for multiple data types from a variety of sensors in a semantic data model for the southern and central portions of the Juan de Fuca Ridge. Currently in progress, and based on that semantic data model, is the development of a metadata archiving and distribution mechanism in support of the NSDI for the northernmost segment of the Juan de Fuca Ridge (www2.ocean.washington.edu/gis).

Related to the concept of metadata is that of spatial lineage, or the history of how the spatial data were derived. The National Committee for Digital Cartographic Data Standards (NCDCDS) has specifically defined lineage as "information describing source materials, as well as the transformations used to derive final digital cartographic data files" [38]. A report of lineage is therefore intended to serve as a communication mechanism between the data producer and the user, a kind of "truth in labeling" statement regarding the nature and quality of GIS-derived products [25]. Because oceanographic data of all kinds often come from a variety of sensors, differing in resolution and covering different geographical areas, lineage documentation is especially important for assessing data quality, data history, and error propagation. The integration of remotely sensed images (such as the aforementioned Geosat gravity data) with in situ data is an important consideration as well. However, the values in remotely sensed images represent parameters in an area whereas the in situ data are point observations. 

The fact that datasets have routinely been collected at different times is a further consideration. The most recent data set is usually assumed to be the most "correct," provided that no special error conditions are known to have affected the sensor. In practice, small variations in time within or between datasets gathered at sea are often ignored to make the analyses and modeling simpler. Mechanisms will need to be put in place to provide information on the source of data input to the GIS, as well as on database and cartographic transformations performed on the data within the GIS, and on input/output relationships between source-, derived- and product-GIS data layers. Lineage documentation is still rarely used in GIS because its structure has not been well understood or well implemented [25]. The studies of Lucas et al. [28] one of the first to investigate metadata and lineage requirements specifically for oceanographic applications, and Lanter [26] are important exceptions. 
.
EXAMPLE FROM THE EASTERN PACIFIC
The list of scientific discoveries in the field of ocean floor mapping continues to grow. To provide an example, the following is a description of work in progress with data from the Northeast (NE) Pacific. A primary goal of U.S. science programs in this region is to assess the temporal
variability of seafloor spreading in the context of observable tectonic, volcanic and hydrothermal processes. Active-process research in the NE
Pacific has involved two basic approaches: 1) long-term instrumentation of multiple in-situ processes in the context of a comprehensive ridge-crest observatory [48] ; and 2) event detection using hydrophone arrays [14]and subsequent response studies in order to characterize transient ridge crest activity [13]. One portion within the Juan de Fuca Ridge, a major seafloor-spreading zone in the NE Pacific, hasbeen chosen as an ocean floor observatory for long-term instrumentation and study: the hydrothermally-vigorous Endeavour Segment. (Figure 4). Work is in progress to integrate accurately-located, high-resolution topographic, photographic, seismic, chemical, geological, biological and acoustic data into a GIS for support of seafloor observatory experiments.

Figure 4. Index map of the Endeavour segment of the Juan de Fuca seafloor-spreading center, northeast Pacific ocean.

A relatively mature GIS data base has been maintained by the VENTS program of NOAA for other portions of the Juan de Fuca Ridge system in which NOAA researchers have focused their efforts over the past decade [3, 60]. However with the addition of the Endeavour segment to the observatory, the community is faced with the dilemma of needing to bring into a readily-accessible medium, the extensive data sets that have accumulated over the years from that segment. NSF has funded an effort to initiate and develop an Endeavour database fully compatible within the existing Juan de Fuca GIS now in place by NOAA (newport.pmel.noaa.gov/gis/data.html). As a wide variety of national and international investigators begin to develop an interest in working within the NE Pacific ROBE sites, ready access to comprehensive and comparable information systems will be essential for effective participation of and contribution from these scientists. Beyond the utility of a GIS for data management, the resulting synergy of different data types within the system provides the scientific community with more information and insight than by considering each type of data separately (Figure 5).

Figure 5. Screen dump of an ArcView session showing various ocean floor data sets from the northeast Pacific. Clockwise from top left: Sea Beam bathymetry overlain with locations of ocean floor markers and rock sample sites; shaded grid of bathymetry overlain with locations of earthquake swarms; bathymetry from submersible overlain with submersible dive tracks and sampling sites; sidescan sonar imagery of an underwater volcano.
Project Approach.  Development of a user-friendly Web site (www2.ocean.washington.edu/gis) is underway, that will allow the community to access Endeavour data in various formats, such as text, Generic Mapping Tools (GMT) grids, and Arc/INFO GIS coverages and grids which are also readable by the ArcView GIS, and to create online maps using the ArcView Internet Map Server of the Environmental Systems Research Institute (see an interactive map gallery of Juan de Fuca data at newport.pmel.noaa.gov/gis/mapindex.html). The site will eventually link to other sites maintained by data contributors. The ultimate configuration of the Endeavour "clearinghouse" will be to provide "one-stop shopping" by obtaining data from various sources, storing the data on a Web server and making the data available to end-users. It may also be possible to inventory analytical procedures developed in recent research projects to integrate various elements into larger process models.

Each data layer in the Endeavour GIS will be accompanied by a text document containing metadata (a standardized, detailed summary of data layer characteristics, with "pointers" to on-line locations and PI contact information). Metadata creation is in progress using a metadata creation tool for the ArcView GIS that parses text in a format acceptable by the FGDC. The FGDC oversees content standards for metadata as directed by the new National Spatial Data Infrastructure (Executive Order 12906 signed by President Clinton in April 1994) which has emerged as one of the strongest programs for information resource management at all levels of government [9].  Maintaining FGDC-compliant metadata for Endeavour GIS layers will provide an important linkage to Federal data clearinghouses maintaining similar records, as well as to allied earth science agencies outside of the seafloor-spreading scientific community.

Currently Available Data.  A major source of ridge crest bathymetric data for Endeavour comes from Lamont-Doherty Earth Observatory's RIDGE Multibeam Synthesis Project. The Endeavour Observatory is located in "Area 12" of that project. The original data for the RIDGE Multibeam Synthesis Project Area 12 Grid were collected by NOAA investigators from the NOAA ships Surveyor and Discoverer. A link on the
Endeavour GIS site has been provided for users to obtain these data directly from the Multibeam web site. Wright et al. [60] have developed a suite of tools for conversion of GMT-style grids and files to GIS format and vice-versa, should users wish to integrate RIDGE Multibeam Synthesis data with existing GIS layers. In 1996, the University of Washington (UW), conducted a survey of the Endeavour Observatory using the Krupp-Atlas Hydrosweep System on the RV Thomas G. Thompson. These data will be available as GMT-style grids and Arc/INFO grids and coverages as ".e00" export files, all with associated metadata.

In addition, the following data sets will be available as GMT-style grids, Arc/INFO grids and coverages as ".e00" export files, and/or text files, all with associated metadata: swath bathymetry, side-scan sonar images, fixed transponder locations, magnetics profiles, and water-column CTD profiles. As submersible navigational precision (through use of "in-hull" data) and accuracy (by referencing to P-code GPS) have improved, there have been problems with registration of features within hydrothermal vent fields. All data collected here have been converted to UTM Zone 9 using the best location for the origin of the UW local Alvin submersible grid as 47˚53.634'N, 129˚ 09.871'W. The following  submersible and ROV data sets will be available as available as GMT-style grids and multi-segment files, Arc/INFO grids and coverages as ".e00 export files, and/or text files, all with associated metadata: Mesotech bathymetry, still imagery, video imagery, submersible dive tracks, samples, fluid chemistry, seafloor markers and geological maps.

Scientific Questions.  Several important scientific questions have arisen from a GIS approach to analyzing these data, chief among them the changing patterns of fissuring with respective to the ages of lava flows. For instance, it was thought previously that the widest (presumably deepest) fissures on the mid-ocean ridge are not primarily eruptive, and should be most abundant in areas of older lava flows, having increased in width with time. However, this has not been observed during high resolution camera surveys of the ocean floor [61].  It is hypothesized that the narrowest, presumably shallowest, fissures correspond to the narrowest, oldest, and most hydrothermally inactive portions of the ridge crest in the survey area. The wide fissures are hypothesized to be the deepest and thus primarily eruptive in origin, whereas the narrow, shallow cracks may be primarily tectonic, and associated more with far-field plate stresses or thermal contraction due to cooling of the crust. 

The intermediate rates of spreading, crustal formation, and even seismicity on the Juan de Fuca Ridge, in comparison to slower-spreading ridges such as the Mid-Atlantic Ridge, beg the question of whether volcanic and tectonic events become larger and more intense, or simply much more frequent [39]. Still to be determined are the implications of these findings for harnessing geothermal energy, garnering oil and mineral wealth (especially the copper, iron, manganese, and zinc found at hydrothermal vents), assessing seismic hazard (particularly tsunami detection and emergency preparation), and finding natural substances that may yield new medicines or new classes of industrial chemicals. Pharmaceutical and biotechnology companies are already analyzing the sulfur-eating bacteria clustered around hydrothermal vents, along with various species of deepsea fish and plants, in the search for a substance that might someday turn into a miracle drug [27]. Says Bruce Robison of the Monterey Bay Aquarium Research Institute, as quoted by Time magazine: “I can guarantee you that the discoveries beneficial to mankind will far outweigh those of the space program over the next couple of decades. If we can get to the abyss regularly, there will be immediate payoffs” [27].

As we cross the physical/human divide to assess the role of humans in the deep ocean processes that they address, we must consider what geographical assessment is needed in order to protect this realm, and what practical uses of the deep ocean (mining,  harvesting of sulfur-eating bacteria, etc.) should be implemented and then increased in the short-term, he mid-term, and the long-term. It is useful to think of these issues of sustainable use within the context of various conservation strategies, which in turn may be linked to issues of deep ocean recreation for island states, as addressed by Trist [54]. Two United Nations documents that are extremely important to consider are Chapter 17 of Agenda 21, as discussed by Vallega [55] and the Law of the Sea Convention. Agenda 21, drafted during the United Nations Conference on Environment and Development in 1992, provides guidelines for the sustainable development of the oceans, with specific references to the detailed gathering of geographic characteristics of regions, the development of information management systems (read GIS), and attention to various issues of information management (collection, analysis, and assessment of spatial data for resource management). The Law of the Sea, entered into force in 1994, enshrines the notion that all problems of ocean space are closely interrelated and should be addressed as a unified system. Marine science research is addressed in Part XII of the document. 

CONCLUSION 
Geography is concerned with the significance of place and space on Earth processes and phenomena. The preceding sections on the contribution of geographers to the science of the ocean floor illustrate the intellectually -rich fodder that awaits other geographers who wish to venture offshore, where 71% of this “place and space” exist. There are enormously important forces at work in the marine environment that are shaping the geography of the planet. These are not likely to be fully understood with existing data sources and imagery. Once again, the importance of community cannot be overstated as it is only through collaboration that the expense and technical expertise of achieving these scientific goals can be realized. Such work requires high levels of government support which are difficult to obtain but not impossible. For example, sharing time at sea does a great amount of oceanographic research. Several principal investigators may be awarded a huge grant (several hundred thousands of dollars to meet the costs of doing fieldwork at sea), and then invite several collaborators to join them to carry out ancillary research. This makes for the most cost-effective use of ship time while requiring the collaborators to seek funds only for the transport of themselves and their equipment to and from port. Geographers have enjoyed high levels of participation in the remote sensing community, another realm of extremely expensive science, but connections to NASA and other agencies within the community have paid off (e.g., the EOSDIS Mission to Planet Earth Information System; see s2k-ftp.cs.berkeley.edu:8000/nasa_e2e). Geographers must continue to build on and expand the tradition of exploratory fieldwork and to foster the appreciation and use of geography by non-geographers, such as ocean scientists, so that “the capacity to make use of [geography’s] perspectives, knowledge, and techniques grows along with the capacity of the discipline to supply them” [45].

aCKNOWLEDGMENTS
The support of the U.S. National Science Foundation, grant OCE-9633609, is gratefully acknowledged. Thanks to Dan Fornari and the Deep Submergence Lab at the Woods Hole Oceanographic Institution. The insightful
comments of Phil Steinberg, Janet Franklin, and AdalbertoVallega significantly improved the manuscript.
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Dawn J. WRIGHT
dawn@dusk.geo.orst.edu
Dawn J. Wright is an assistant professor in the Department of Geosciences at Oregon Statue University, where she is responsible for teaching, research, and campus leadership in GIS. Additionally, she holds an adjunct appointment in the Oregon State College of Oceanic and Atmospheric Sciences and collaborates with faculty and students in the Marine Geology and Marine Resource Management programs. Dawn Wright is a member of the GISPlanet International Committee.

Dawn's research focuses on application and analytical issues in GIS for oceanographic, particularly data conversion, management, and metadata. She is also interested in web-based GIS and the geography of Cyberspace. Other research interests include the relationships between volcanic, hydrothermal and tectonic processes at seafloor-spreading centers, and the analysis and interpretation of data from deepsea mapping systems.

Dawn joined the faculty of Oregon State in 1995, having completed a Ph.D. in physical geography and marine geology at the University of California at Santa Barbara and a post-doc at the NOAA Pacific Marine Environmental Laboratory in Newport, Oregon. She has also spent several years at sea as a marine technician for the Ocean Drilling Program and as a shipboard scientist on various research vessels in the U.S. University National Oceanographic Laboratory System.
Oregon State University
Department of Geosciences
104 Wilkinson Hall
Corvallis, OR 97331-5506
USA
Tel: +1.541-737-1229
Fax: +1.541-737-1200
URL: http://dusk.geo.orst.edu