U.S. Department of the Interior

U.S. Geological Survey

Open-File Report 2009–1266

Constructing Uniform Resource Locators 

(URLs) for Searching the Marine Realms 

Information Bank
Constructing Uniform Resource Locators 

(URLs) for Searching the Marine Realms 

Information Bank

By Guthrie A. Linck, Alan O. Allwardt, and Frances L. Lightsom

Open-File Report 2009–1266

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia: 2009

For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, 

natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS

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visit http://www.usgs.gov/pubprod

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Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the 

U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Linck, G.A., Allwardt, A.O., and Lightsom, F.L., 2009, Constructing Uniform Resource Locators (URLs) for searching 

the Marine Realms Information Bank: U.S. Geological Survey Open-File Report 2009–1266, 13 p., available at 

http://pubs.usgs.gov/of/2009/1266.
iii

Contents

Abstract...........................................................................................................................................................1

Introduction.....................................................................................................................................................1

Why Construct Search URLs? ............................................................................................................1

The MRIB Search URL Structure ................................................................................................................2

What is CGI? ..........................................................................................................................................2

Parameter Types ...................................................................................................................................2

Tables of Parameters ....................................................................................................................................2

References Cited............................................................................................................................................3

Tables

1. General parameters and basic actions.....................................................................................4

2. Electronic Index Card (EIC) field parameters...........................................................................5

3. Table parameters........................................................................................................................10

4. Facet (category) parameters....................................................................................................10

5. Map parameters and actions ...................................................................................................11
Abstract

The Marine Realms Information Bank (MRIB) is a 

digital library that provides access to free online scientific 

information about the oceans and coastal regions. To search 

its collection, MRIB uses a Common Gateway Interface 

(CGI) program, which allows automated search requests using 

Uniform Resource Locators (URLs). This document provides 

an overview of how to construct URLs to execute MRIB 

queries. The parameters listed allow detailed control of which 

records are retrieved, how they are returned, and how their 

display is formatted.

Introduction

The Marine Realms Information Bank (MRIB; 

http://mrib.usgs.gov) was developed in 2001 by the U.S. 

Geological Survey (USGS) Coastal and Marine Geology 

Program (CMGP) in partnership with the Woods Hole 

Oceanographic Institution (WHOI). The MRIB is a distributed 

digital geolibrary of worldwide coastal and marine scientific 

information, created with the desire to provide an alternative 

to a standard Web search engine. MRIB serves the needs 

of a diverse audience, including scientists, public servants, 

advocacy groups, educators, and concerned citizens. For 

a more complete description of MRIB, see Lightsom and 

Allwardt (2007; 2009).

The MRIB is an online catalog of Electronic Index Cards 

(EICs), in which the cards contain many metadata parameters that describe the content of the referenced information 

resources. Multiple methods of searching for information are 

offered and are designed to be intuitive and effective in allowing the user to obtain relevant results. 

Many of the metadata fields, or facets, provided in the 

MRIB are hierarchical in nature and indexed using controlled 

vocabularies of standardized terms; one of these facets is a 

dictionary of place names, or gazetteer. The MRIB faceted 

classification provides users with guidance in searching 

and encourages them to find information using a top-down 

approach. An analogy that demonstrates the advantage of such 

a search system would be a sequential key system that guides 

the user with a series of questions to determine the species of 

a particular animal instead of having the user type descriptive 

keywords of the animal into a standard Web search engine. 

The unguided Web search requires the user to try many combinations of keywords, visit the retrieved Web sites, and wade 

through irrelevant results. The descriptive keyword approach 

is inefficient because there are so many ways to describe the 

same entity. The sequential key, in contrast, is structured to 

provide guidance and allow the user to more effectively make 

the determination.

Why Construct Search URLs?

Knowing how to construct MRIB search URLs and 

knowing how the search parameters work will allow users 

to harvest MRIB metadata records without using the online 

search interface. Automated harvesting could be especially 

useful to organizations that have compiled their own databases 

of online scientific information and want to search the MRIB 

for specific authors or topics. Established databases that 

overlap in content with MRIB include the Digital Library for 

Earth System Education (http://www.dlese.org/), the NASA 

Global Change Master Directory (http://gcmd.nasa.gov/), 

and the National Science Digital Library (http://nsdl.org/), 

among others. 

Using the EIC modification time parameter (eic.modified, 

recorded whenever any metadata record is changed), one 

can search the MRIB for new or corrected records matching 

certain criteria. A previously harvested record should be 

checked periodically to see if the corresponding MRIB 

metadata profile has been modified. For example, if the URL 

of an online information resource changes because the host 

institution has restructured its entire URL system, the MRIB 

metadata profile must be modified to eliminate the dead link. 

Because distributed digital libraries like MRIB store the 

URLs of online information resources, not their content, it is 

essential to maintain valid links to the original resources. 

Constructing Uniform Resource Locators (URLs) for 

Searching the Marine Realms Information Bank

By Guthrie A. Linck, Alan O. Allwardt, and Frances L. Lightsom
2 Constructing Uniform Resource Locators (URLs) for Searching the Marine Realms Information Bank

The MRIB Search URL Structure

The structure of an MRIB search URL is fairly simple 

and consists of two parts, separated by a question mark (?). 

The first part is the URL of the Common Gateway Interface 

(CGI) program, in this case http://mrib.usgs.gov/

cgi-bin/search. The second part consists of a list of 

name=value pairs separated by ampersands (&), which 

specify the values of the search parameters passed to the CGI 

program. Thus, to add another search parameter one simply 

includes the appropriate &name=value string at the end of 

the URL. 

Accordingly, a simple search request for records matching the single value Environment > Climate Change in the 

Hot Topics field is executed using this URL: http://

mrib.usgs.gov/cgi-bin/search?mrib.

topics=environment.climate_change. 

A more complex example, which includes several 

search criteria and requests an Extensible Markup Language (XML) export of the retrieved records, is the following: http://mrib.usgs.gov/cgi-bin/

search?mrib.topics=environment.climate_

change&mrib.topics=hazards_and_disasters.erosion&general.author=sallenger,_

asbury_h.,_jr.&cmd=ExportCards&export_

format=xml. 

Most non-alphanumeric characters that are passed to the 

CGI, either in the names or the values, must employ URL 

encoding, which consists of a percent symbol (%) followed by 

the two-digit hexadecimal representation of the special character. URL encoding is discussed in greater detail by Wilson 

(2003) and by Berners-Lee and others (1994).

What is CGI?

The Common Gateway Interface (CGI) is a protocol 

created to provide a standard method of interfacing external 

programs to an information server in a platform-independent 

manner. Unlike static HTML Web pages, which are simply 

retrieved as is, CGI programs are executed dynamically to 

provide customized content with each invocation. One of the 

most common types of CGI program is an interactive search 

service providing access to information from a database server 

on the Internet. The MRIB falls within this category.

CGI is explained in more detail at a Web site maintained 

by the National Center for Supercomputing Applications 

(http://hoohoo.ncsa.illinois.edu/cgi/overview.html). Robinson 

and Coar (2004) give a technical description of CGI. An excellent source for additional Web-related information is the World 

Wide Web Consortium (http://www.w3.org/).

Parameter Types

The MRIB search CGI uses five basic types of parameters. Basic action parameters determine how the results are 

displayed or used; an example would be cmd=ViewMap, 

which displays search results on a geographical map. Electronic Index Card (EIC) field parameters are used to limit the 

search to those records that match specified values in certain 

fields; an example would be general.title=seafloor, 

which will match records with the string “seafloor” in the 

title. Table parameters determine how the table of search 

results is displayed and used; an example would be rows=50

to display 50 records per page in a table of search results. 

Map parameters determine the appearance of the map and 

how search results are depicted on it; an example would be 

proj=m, which employs the Mercator projection for the map 

display. Finally, facet parameters determine how the MRIB 

facets indexing categories are displayed to guide a topical 

search; an example would be maxdepth=2, which displays 

the first three levels in a facet hierarchy. 

Tables of Parameters

The following tables list all search URL parameters that 

can be passed to the basic MRIB search CGI (http://

mrib.usgs.gov/cgi-bin/search) to refine a specific 

search request. The parameter tables below are organized into 

three columns. 

Parameter: Name of the parameter, as well as any 

synonyms. The first parameter name (in bold) is the 

primary name used in the underlying code. The synonyms are provided for ease of use; some are former 

names from previous versions of MRIB.

Arguments: Number of values that may be specified 

for each parameter. Parameters with 1 in the Arguments column accept only one value; parameters 

with an asterisk in the Arguments column accept 

multiple values. The single-value parameters may 

be specified multiple times in the URL, but only 

one value will be recognized (usually the last value, 

but the order in which they are passed to the MRIB 

search CGI will be browser dependent, and therefore 

not well defined).

Description: How the parameter functions.

The five tables include parameters that govern different functions of the MRIB search. 
References Cited 3

1. General parameters and basic actions (table 1) 

determine which of several basic MRIB Web pages 

are generated to guide the search and report the 

results: facet (category) view, for topical searches; 

map view, for geographic searches; table view, for 

viewing and sorting the search results; and export 

view, for harvesting MRIB records.

2. Electronic Index Card (EIC) field parameters

(table 2) correspond to the EIC metadata fields and 

determine which MRIB records are selected by 

the search.

3. Table parameters (table 3) determine the format of 

a Web page that displays a table of search results: 

records per page, sort field, sort order, and so on.

4. Facet (category) parameters (table 4) determine the 

format of a Web page that lists the controlled vocabulary of a selected facet (indexing category): for 

example, the depth of the hierarchy to be displayed.

5. Map parameters and actions (table 5) determine 

the appearance of a Web page that displays search 

results on a map: bounding coordinates, scale, 

representation of relief, resolution, and so on.

References Cited

Berners-Lee, T., Masinter, L., and McCahill, M., eds., 1994, 

Uniform Resource Locators (URL), Internet Engineering 

Task Force RFC 1738, available at http://www.ietf.org/rfc/

rfc1738.txt.

Lightsom, F.L., and Allwardt, A.O., 2007, The Marine Realms 

Information Bank family of digital libraries—Access to free 

online information for coastal and marine science: U.S. 

Geological Survey Fact Sheet 2007–3025, 2 p., available at 

http://pubs.usgs.gov/fs/2007/3025/.

Lightsom, F.L., and Allwardt, A.O., 2009, USGS digital 

libraries for coastal and marine science, in Theng, Y.-L., 

and others, eds., Handbook of research on digital libraries—

Design, development, and impact: Hershey, Pa., 

Information Science Reference, p. 421–430, available at 

http://mrib.usgs.gov/doc/handbook.pdf.

Robinson, D., and Coar, K., 2004, The Common Gateway 

Interface (CGI) Version 1.1: Internet Engineering Task 

Force RFC 3875, available at http://www.ietf.org/rfc/

rfc3875.txt.

Wilson, Brian, 2003, URL encoding (or: ‘What are those 

“%20” codes in URLs?’), available at http://www.blooberry.

com/indexdot/html/topics/urlencoding.htm.
4 Constructing Uniform Resource Locators (URLs) for Searching the Marine Realms Information Bank

Table 1. General parameters and basic actions.

Parameter Arguments Description

cmd, 

action, 

a

1 Specifies the action to take after the search has been performed. All valid actions begin with a capital 

letter, including basic actions such as ViewTable, ViewMap, ViewFacet, and ExportCards (below) 

and map actions such as ZoomIn, ZoomOut, and ZoomReset (table 5). Actions can be specified using 

the cmd parameter (for example, cmd=ViewTable) or by passing the action directly (for example, 

ViewTable=1). In the second instance, the action accepts Boolean (1/0) values: if the value is 0

(or an empty string), then the parameter will be ignored; if the value is 1, then the action will be taken. 

Some action parameters, such as Compass and Imap (table 5), also have P.x and P.y counterparts to 

work with image maps.

NewSearch 1 Returns to the search home page. Accepts Boolean (1/0) values.

ViewTable 1 Displays the current search results in a table. Accepts Boolean (1/0) values.

ViewMap 1 Displays the current search results on a map. Accepts Boolean (1/0) values.

ViewFacet 1 Displays the current search results in the context of a selected facet (indexing category). Accepts Boolean 

(1/0) values. Used in conjuction with the facet parameter.

ExportCards 1 Exports the current search results. Accepts Boolean (1/0) values. Used in conjuction with the 

export_format parameter (if no format is specified, an export menu will be displayed).

ViewSelections,

ViewCards

1 Used in conjunction with the idlist parameter to select and display individual records from a previously 

generated table of search results. Accepts Boolean (1/0) values.

RemoveSelections, 

RemoveCards

1 Used in conjunction with the idlist_x parameter to remove individual records from a previously generated table of selections. Accepts Boolean (1/0) values.

ContinueSearch 1 Returns the user from a table of selections to the original table of search results. Accepts Boolean (1/0) 

values.

user 1 Parameter specifying the user interface to display. Three values are currently recognized: mrib for the 

Marine Realms Information Bank (the default); cch for the Coastal Change Hazards Digital Library; 

and mbs for the Monterey Bay Science Digital Library.
Table 2 5

Table 2. Electronic Index Card (EIC) field parameters.—Continued

Parameter Arguments Description

eic.id, 

id

1 Unique, eight-character hexadecimal identifier assigned by the MRIB Administrator to 

each EIC (record) in an MRIB top-level directory. All EICs matching the specified 

ID number or partial ID number are retrieved (matched left to right if fewer than 

eight characters are specified). Basic searches retrieve EICs from /mrib (the default 

top-level directory), unless a different top-level directory is specified (see eic.file).

eic.file, 

file

1 Specifies the nested directory and file structure in which an EIC is stored. The top-level 

directories include /mrib (the publicly available database), /contrib (usercontributed EICs), and individual user accounts (provisional EICs). This parameter 

limits the search to records in the given directory or file. For example, most of the records found in the Coastal Change Hazards Digital Library are stored in the mrib/

cch directory.

eic.type, 

type

1 Specifies the type of record to be searched: single documents (0|item) or collections 

(1|collection), reflecting the nature of the referenced information resources.

eic.collection 1 Not currently utilized as an indexing parameter. The default value for collection records 

is eic.collection=* (see also eic.type).

eic.public_id, 

eic.pid, 

pid, 

public_id

1 Assigned by the MRIB Administrator to track user-contributed EICs that have been 

incorporated into the publicly available database. The public database IDs shown in 

the /contrib directory correspond to the EIC IDs in the /mrib directory. Search 

is performed in the same way as in the eic.id field.

eic.accession_id, 

eic.submission_id, 

eic.sid, 

eic.submit_id, 

sid, 

submission_id, 

submit_id

1 Assigned by the MRIB Administrator to track provisional, user-contributed EICs awaiting review. The Accession IDs shown in the /mrib directory correspond to the 

EIC IDs in the /contrib directory. Search is performed in the same way as in the 

eic.id field.

eic.created, 

eic.ctime

1 Date the EIC was created (may differ from date the EIC was completed and submitted 

to the MRIB Administrator for review). See date formats.1 Prefix with < to search for 

records created before the specified date or with > to search for records created after 

the specified date.

eic.modified,

eic.mtime

1 Date the EIC was last modified. See date formats.1 Prefix with < to search for records 

modified before the specified date or with > to search for records modified after the 

specified date.

eic.submitted, 

eic.stime

1 Date the EIC was submitted to the MRIB Administrator for review and incorporation 

into the publicly available database. See date formats.1

 Prefix with < to search for 

records submitted before the specified date or with > to search for records submitted 

after the specified date.

eic.indexer, 

indexer

* The name and email address of the person who created or modified the EIC. Stored values are in the format Last,_First_Middle name@email.com (the middle 

name or initial and email address are optional). Search is performed using simple 

string matching.2

eic.indexer_comments, 

eic.comments, 

indexer_comments

1 Additional information about the indexed information resource or the EIC itself. Search 

is performed using simple string matching.2

eic.rules 1 Limits the search to records created under a specific set of cataloging rules. At present, 

two sets of rules are recognized: mrib, which employs the generalized Hot Topics3

controlled vocabulary (the default), and cch, which employs the specialized Coastal 

Change Hazards Topics3 controlled vocabulary. Search is performed using simple 

string matching.2

general.url, 

url

1 Uniform Resource Locator (URL) for the referenced information resource. Search is 

performed using simple string matching.2
6 Constructing Uniform Resource Locators (URLs) for Searching the Marine Realms Information Bank

Table 2. Electronic Index Card (EIC) field parameters.—Continued

Parameter Arguments Description

eic.url_active, 

url_active

1 Indicates the status of the URL for the referenced information resource: active (0) or 

not active (1). This database management parameter is not currently utilized.

general.title, 

title

1 Title of the referenced information resource. Search is performed using simple string 

matching.2

general.custodian, 

general.curator, 

general.poc, 

custodian, 

curator, 

poc

* The name and email address of the person responsible for providing the information 

resource on a Web site (and who normally responds to inquiries about this Web site 

and its content). Stored values are in the format Last,_First_Middle name@

email.com (the middle name or initial and email address are optional). A custodial 

title (for example, Agency_Webmaster) may be listed in place of a personal 

name. The URL of a “Contact Webmaster” Web form may be substituted for the 

email address. Search is performed using simple string matching.2

general.description, 

general.desc, 

description, 

desc

1 Basic description of the content of the referenced information resource. Search is 

performed using simple string matching.2

general.date, 

general.modified, 

general.modified_date, 

modified, 

modified_date

1 Date on which the referenced information resource was created or last modified. See 

date formats.1 Prefix with < to search for information resources predating the specified date or with > to search for information resources postdating the specified date.

general.content_start_date, 

general.content_start, 

general.content_begin_date, 

general.content_begin, 

content_start_date, 

content_start, 

content_begin_date, 

content_begin

1 Starting date (and time, if applicable) of the intellectual content in the information 

resource. See date formats.1 Prefix with < to search for content starting before the 

specified date or with > to search for content starting after the specified date.

general.content_end_date, 

general.content_end, 

content_end_date, 

content_end

1 Ending date (and time, if applicable) of the intellectual content in the information 

resource. See date formats.1 Prefix with < to search for content ending before the 

specified date or with > to search for content ending after the specified date.

general.mean_longitude, 

general.mean_lon, 

general.longitude, 

general.lon, 

mean_longitude, 

mean_lon, 

longitude, 

lon

1 Mean longitude of the study area referenced in the information resource (if applicable). 

This field is not currently implemented as a search parameter.

general.mean_latitude, 

general.mean_lat, 

general.latitude, 

general.lat, 

mean_latitude, 

mean_lat, 

latitude, 

lat

1 Mean latitude of the study area referenced in the information resource (if applicable). 

This field is not currently implemented as a search parameter.
Table 2 7

Table 2. Electronic Index Card (EIC) field parameters.—Continued

Parameter Arguments Description

general.west_longitude, 

general.west_lon, 

west_longitude, 

west_lon, 

x0

1 West bounding coordinate of the study area referenced in the information resource 

(if applicable). See degree formats.4 Note: geographic searches are usually specified 

using mrib.location or the zoom parameter.

general.east_longitude, 

general.east_lon, 

east_longitude, 

east_lon, 

x1

1 East bounding coordinate of the study area referenced in the information resource 

(if applicable). See degree formats.4 Note: geographic searches are usually specified 

using mrib.location or the zoom parameter.

general.north_latitude, 

general.north_lat, 

north_latitude, 

north_lat, 

y1

1 North bounding coordinate of the study area referenced in the information resource 

(if applicable). See degree formats.4 Note: geographic searches are usually specified 

using mrib.location or the zoom parameter.

general.south_latitude, 

general.south_lat, 

south_latitude, 

south_lat, 

y0

1 South bounding coordinate of the study area referenced in the information resource 

(if applicable). See degree formats.4 Note: geographic searches are usually specified 

using mrib.location or the zoom parameter.

general.mean_elevation, 

general.mean_elev, 

general.elev, 

mean_elev, 

mean_elevation, 

elev

1 Mean elevation (in meters) of the study area described in the referenced information 

resource (if applicable). Prefix with < to search for elevations below the specified 

value or with > to search for elevations above the specified value.

general.upper_elevation, 

general.upper_elev, 

upper_elevation, 

upper_elev

1 Highest elevation (in meters) of the study area described in the referenced information 

resource (if applicable). Prefix with < to search for elevations below the specified 

value or with > to search for elevations above the specified value.

general.lower_elevation, 

general.lower_elev, 

lower_elevation, 

lower_elev

1 Lowest elevation (in meters) of the study area described in the referenced information 

resource (if applicable). Prefix with < to search for elevations below the specified 

value or with > to search for elevations above the specified value.

general.keywords, 

keywords, 

keyword

* Searches both the controlled-vocabulary terms (see below) and free-text keywords that 

were used to index the information resource. Search is performed using simple string 

matching.2

general.author, 

author

* Limits search to records matching one or more of the specified authors (persons responsible for the intellectual content of the information resource). See the list of registered Authors.3

 Note that MRIB does not employ “corporate authors” (this information is conveyed in the Agency field).

mrib.agency, 

agency

* Limits search to records matching one or more of the specified agencies (organizations 

that contributed to the information resource, by funding or conducting research, 

interpreting or compiling data, publishing a document, hosting a Web site, and so 

on.). See the list of registered Agencies.3

mrib.discipline, 

discipline

* Limits search to records matching one or more of the specified disciplines (academic 

fields relevant to the scientific research or issues discussed in the information 

resource). See the list of registered Disciplines.3

mrib.location, 

loc, 

location

1 Limits search to records matching the specified gazetteer location. See the list of 

registered Gazetteer Locations.3
8 Constructing Uniform Resource Locators (URLs) for Searching the Marine Realms Information Bank

Table 2. Electronic Index Card (EIC) field parameters.—Continued

Parameter Arguments Description

mrib.feature_type, 

mrib.feature, 

feature_type, 

feature

* Limits search to records matching one or more of the specified feature types (the 

generic features, geographic and otherwise, with which the information resource is 

concerned). See the list of registered Feature Types.3

mrib.biota, 

biota

* Limits search to records matching one or more of the specified biota (using the common names of organisms, arranged in five kingdoms: animals, plants, fungi, protists, 

and bacteria). See the list of registered Biota.3

general.content_type, 

content_type

* Limits search to records matching one or more of the specified content types (the 

intellectual form of the information resource, based on the Dublin Core Metadata 

Initiative Type Vocabulary). See the list of registered Content Types.3

mime.file_type, 

file_type

* Limits search to records matching one or more of the specified file types (the 

transmission form of the information resource, based on MIME media type/subtype 

assignments). See the list of registered File Types.3

mrib.topics, 

mrib.hot_topics, 

topics, 

hot_topics

* Limits search to records matching one or more of the specified Hot Topics (issues of 

concern to scientists, policymakers, and the general public). See the list of registered 

Hot Topics.3 Note: Hot Topics are employed in the MRIB and MBS user interfaces 

(see user). See also eic.rules.

cch.topics * Limits search to records matching one or more of the specified Coastal Change Hazards 

Topics (issues of concern to scientists, policy makers, and the general public). See 

the list of registered CCH Topics.3 Note: CCH Topics are employed in the CCH user 

interface (see user). See also eic.rules.

mrib.method, 

method

* Limits search to records matching one or more of the specified research methods (techniques employed to collect and analyze the scientific data discussed in the information resource). See the list of registered Research Methods.3

mrib.project, 

project

* Limits search to records matching one or more of the specified projects (using project 

names as specified in the information resource, which may differ from the formal 

project titles employed by the parent agency for its administrative purposes). See the 

list of registered Projects.3

mrib.geologic_time, 

mrib.geological_time, 

mrib.geotime, 

geologic_time, 

geological_time, 

geotime

* Limits search to records matching one or more of the specified units of geologic time 

addressed in the information resource (eon, era, period, and epoch). See the list of 

registered Geologic Times.3

mrib.parent_name, 

parent_name

1 Name of the Web-based collection to which the referenced information resource belongs (reflecting the internal linking structure of the Web site). Search is performed 

using simple string matching.2

mrib.parent_url, 

parent_url

1 URL of the Web-based collection to which the referenced information resource belongs 

(reflecting the internal linking structure of the Web site). Search is performed using 

simple string matching.2

mrib.collection_coverage, 

mrib.coverage, 

collection_coverage, 

coverage

1 For collection records only. A phrase-length indication of the scope of the collection. 

Search is performed using simple string matching.2

mrib.collection_count, 

mrib.count, 

collection_count, 

count

1 For collection records only. Number of items in the indexed collection (for example, 

digital photos in an online database; hyperlinks in an online directory; individual 

pages in a Web site). Not currently implemented as a search parameter.
Table 2 9

Table 2. Electronic Index Card (EIC) field parameters.—Continued

Parameter Arguments Description

mrib.collection_update_frequency,

mrib.update_frequency, 

mrib.update, 

collection_update_frequency, 

update_frequency, 

update

* For collection records only. Limits search to records matching one or more of the specified collection update frequencies. See the list of registered Update Frequencies.5

mrib.collection_alert, 

mrib.alert, 

collection_alert, 

alert

1 For collection records only. Notes about dormant collections, the regular removal of 

data from time-sensitive collections, and so on. Search is performed using simple 

string matching.2

mrib.subset, 

subset

* Limits the search to records assigned by the indexer to one or more subsets of the 

MRIB database. The MRIB database currently includes two subsets: Coastal_

Change_Hazards (displayed in the Coastal Change Hazards Digital Library) and 

Monterey_Bay_Science (displayed in the Monterey Bay Science Digital 

Library).

1 Dates and times use the format yyyy/mm/dd hh:mm:ss (mm/dd and hh:mm:ss are optional). Times follow the 24-hour clock convention. For sorting purposes, a less specific date (for example, 1999) predates a more specific date (for example, 1999/5). 

2 MRIB uses simple case-insensitive substring matching. Search values beginning with a forward slash (/) are interpreted as Perl regular expressions, 

allowing the experienced programmer to construct complex queries using Boolean and comparison operators. See the Perl Regular Expressions Tutorial

(http://perldoc.perl.org/perlretut.html) and examples from the MRIB Advanced Search Form (http://mrib.usgs.gov/cgi-bin/search?advanced=1#Examples). 

3 The MRIB controlled vocabulary is online at http://mrib.usgs.gov/doc/facets.html.

4 Geographic coordinates are stored internally as decimal degrees (dd.ddd) but also may be specified in degrees, minutes, and seconds (dd:mm:ss). 

Longitude values may be expressed in three formats: -180 to 180, 180W to 180E, or 0 to 360. Latitude values may be expressed in two formats: -90 to 90 or 

90S to 90N.

5 The list of update frequencies is online at http://mrib.usgs.gov/meta/collection_update_frequency.html.
10 Constructing Uniform Resource Locators (URLs) for Searching the Marine Realms Information Bank

Table 3. Table parameters.

Parameter Arguments Description

start, 

startrec

1 In a sequential table of search results, the start parameter specifies the first record to be displayed in the 

table. The default setting is start=0, which displays record 1 first. (Note: the first record displayed 

also depends on the sort and order parameters, described below.)

stop, 

stoprec

1 In a sequential table of search results, the stop parameter specifies the last record to be displayed in the 

table.

rows 1 Specifies the number of rows per page in a table of search results. The default setting is 10 rows per page.

page 1 In a multipage table of search results, the page parameter specifies the first page to be displayed. The default 

setting is page=0, which displays page 1 first. (The records included on the first page to be displayed 

will also depend on the rows parameter. Example: page=1 and rows=10 will display page 2 first, with 

records 11–20.)

sort, 

sortfield, 

sort_field

1 Specifies the field used to sort a table of search results. The default field for sorting is general.author, but 

any other field in the table may be used: eic.type, general.title, or general.date. Search results may also 

be sorted by fields not normally shown in the table, such as eic.id, general.content_start_date, and 

general.content_end_date.

order, 

sortorder, 

sort_order

1 Specifies the sort order in a table: ascending (+|up) or descending (-|down). The default sort order is 

ascending for all fields except time and date fields.

idlist, 

id_list

* Parameter used in conjunction with ViewSelections to select and display individual records from a previously generated table of search results. Multiple instances of this parameter may be passed. The format is 

hexadecimal (see eic.id).

idlist_x, 

id_list_x, 

id_x

* Parameter used in conjunction with RemoveSelections to remove individual records from a previously generated table of selections. Multiple instances of this parameter may be passed. The format is hexadecimal 

(see eic.id).

export_format,

export_fmt, 

export

1 Parameter used in conjunction with ExportCards to specify the format of exported search results. The available export formats1

 include plain text (txt), comma-separated values (csv or csv_int), Extensible 

Markup Language (xml), Keyhole Markup Language (kml), and Electronic Index Card format (eic_

mod). The latter is the internal format used to store records in the MRIB database.

1

 MRIB export formats are described in more detail at http://mrib.usgs.gov/doc/export.html.

Table 4. Facet (category) parameters.

Parameter Arguments Description

facet, 

f, 

category

1 Specifies the facet to search. Used in conjunction with the facet_value parameter and any basic action 

(ViewTable, ViewMap, ViewFacet, or ExportCards).

facet_value, 

fvalue, 

fv, 

category_value

1 Used in conjunction with the facet parameter to specifiy a particular facet value. Facet values may be specified by name, ID, or ID span (for example, see Agency facet: http://mrib.usgs.gov/meta/agency.html).

maxdepth, 

depth, 

level

1 Used in conjunction with the facet parameter and ViewFacet to specify the number of levels to display in a 

facet hierarchy. The default display is two levels (maxdepth=1).
Table 5 11

Table 5. Map parameters and actions.—Continued

Parameter Arguments Description

geosearch 1 Specifies how geographic searches are performed: 0|mean (the default) finds study areas whose 

center points (mean latitude and longitude) are located in the current map region; 1|within

finds study areas that fall entirely within the current map region; 2|contains finds study 

areas that completely encompass the current map region; 3|intersects finds study areas that 

intersect the current map region.

imap_action 1 Specifies the action taken when clicking on the map: 0|ZoomIn (the default) zooms in on the 

click point; 1|auto either selects a table of search results or zooms in, depending on the density 

of search results at the click point; 2|select|table selects a table of search results for the 

click point; 3|ZoomOut zooms out from the click point; 4|pan|center recenters the map on 

the click point.

zoom 1 Limits the search to the specified geographic bounding box. The format is W/E/S/N, with coordinates expressed either in decimal degrees or in degrees, minutes, and seconds (see deg_format). 

Note: the four bounding parameters that define a specific study area may also be searched: 

see general.west_longitude, general.east_longitude, general.north_latitude, and 

general.south_latitude.

zoomloc 1 Internal parameter that manages complex geographic searches. If a gazetteer location is selected 

first and an overlapping zoom location is selected second, then zoomloc=0. In this instance, 

ZoomReset will cancel the zoom location and save the gazetteer location. If a zoom location is 

selected first and an overlapping gazetteer location is selected second, then zoomloc=1. In this 

instance, ZoomReset will cancel both locations.

scale, 

map_scale

1 A relative scale from 3 (narrow) to 20 (wide), with 6 being the default setting.

proj, 

projection, 

map_projection

1 The following Generic Mapping Tools (GMT) map projections1 are currently supported: Mercator 

(m), basic cylindrical (y), equidistant cylindrical (q), and polar (p).

pproj 1 Internal field containing information about the previous map, used to determine how to generate the 

next map. The format is PM/S, where P is the projection, M is the median longitude (in 0–360 

degree format), and S is the scale.

relief 1 Specifies the type of base map to be generated: shaded relief or outline. Shaded relief maps in 

MRIB employ the following GMT built-in color palettes1 for elevation tinting: relief, 

globe|global, topo, and sealand. The simple color schemes for outline maps include bw

(uncolored), gb (green and blue), and bb (brown and blue). The shaded relief maps take longer 

to generate than the outline maps.

res, 

resolution, 

map_resolution

1 Specifies the resolution of physical features on shaded relief maps (not applicable to outline maps). 

The five GMT resolutions1 are f|full, h|high, m|medium, l|low, and c|crude. The 

default resolution is m|medium. Higher resolution maps take longer to generate.

deg_format 1 Specifies the format of latitude and longitude values. To display degrees, minutes, and seconds (the 

default setting in the MRIB map interface), use deg_format=dd:mm:ss. To display decimal 

degrees, use deg_format=dd.ddd (three decimal places being the practical limit). Either 

format may also accept a plus sign (encoded as %2B) as the leading character, in which case the 

following conventions will be employed: -90 to 90 for latitude and 0 to 360 for longitude.

dpi, 

dots_per_inch

1 Specifies the dots per inch when generating map images. A larger dpi value will produce a higher 

resolution image, but the map will also take longer to generate. The default setting is dpi=200.

image_type, 

img_type, 

img

1 Specifies the image format for generating maps: JPEG|JPG, PNG, or GIF. The default image 

format is JPEG.

xy 1 Internally used field specifying the width and height of the previous map image, in pixels (for 

example, xy=540x320).

area 1 Specifies the bounding coordinates of the map display. The format is W/E/S/N (see also 

deg_format). The area parameter overrides the zoom parameter in order to change the map 

display without changing the search coordinates.
12 Constructing Uniform Resource Locators (URLs) for Searching the Marine Realms Information Bank

Table 5. Map parameters and actions.—Continued

Parameter Arguments Description

basemap 1 Specifies the bounding coordinates of the initial base map. The format is W/E/S/N (see also 

deg_format). The default setting is the world map: basemap=180W/180E/90S/90N.

zoomratio 1 Specifies the rate of change when zooming in or out of the current map region. The user interface 

employs three rates: 3.0|fast (the linear extent of the map, in degrees, changes by a factor of 3), 2.0|medium (factor of two), and 1.5|slow (factor of 1.5). The default setting is 

2.0|medium.

panratio 1 Specifies the rate of panning in map view when clicking on the compass image (see Compass.x and 

Compass.y). The default setting is 0.80, subject to an additional multiplier defined by the click 

point.

minsize 1 Minimum linear dimension of a zoomed-in map, in decimal degrees. The default setting is 0.667.

plot_matches 1 Specifies how geographic search results (matches) are depicted on the map: 0|off hides all 

matches; 1 displays the footprints of larger study areas; 2 depicts larger study areas as footprints 

and point studies as symbols (see below); 3 displays point studies only; 4|on (the default) 

depicts all studies as symbols (using center points for larger study areas).

symbol, 

sym, 

plot_symbol, 

plotsym

1 Specifies the type and size of the symbol that is used for plotting matches on the map (see 

plot_matches). The format is cN, where c is the symbol type and N is the size. The available 

symbol types are: c|circle, a|star, t|triangle, s|square, d|diamond, and 

x|cross. The default setting is symbol=c0.075.

symbol_pen 1 Specifies the thickness and color of the GMT pen1

 that is used for outlining the symbol. The format 

is width/red/green/blue. The default setting is 1/0/0/0, a black line one pixel wide.

symbol_fill, 

symbol_color

1 Specifies the interior color of the symbol. The format is red/green/blue, with a default setting 

of 225/30/30. See GMT area fill attributes1 for more information.

study_pen 1 Specifies the thickness and color of the GMT pen1

 that is used for highlighting the footprints of 

study areas (see plot_matches). The format is width/red/green/blue, with a default setting of 1/225/30/30.

Imap.x and 

Imap.y

1 The x/y values (in pixels) of the click point on the map image.

Compass.x and 

Compass.y

1 The x/y values (in pixels) of the click point on the compass image.

ZoomIn, 

Zoom

1 Zooms into the center of current map region.

ZoomOut 1 Zooms out from the center of current map region.

ZoomReset 1 Removes the bounding-box coordinates defining the current map region.

WorldMap, 

WorldView

1 Displays the current map region on the world map.

RegionMap 1 Reverses the action of WorldMap.

border 1 Displays political boundaries. The current settings: border=off hides all political boundaries; 

border=1 displays national boundaries; border=2 (the default) displays national boundaries and USA State boundaries; border=4 displays national boundaries and USA State/county 

boundaries (counties are displayed only if they can be resolved at the scale of the current base 

map).

topo250k 1 Displays USGS 1:250,000 topographic map outlines (coastal USA only). The settings: 

topo250k=off (the default) hides the outlines; topo250k=on displays the outlines; 

topo250k=auto displays the outlines only if they can be resolved at the scale of the current 

base map.

topo24k 1 Displays USGS 1:24,000 topographic map outlines (coastal USA only). The settings: 

topo24k=off (the default) hides the outlines; topo24k=on displays the outlines; 

topo24k=auto displays the outlines only if they can be resolved at the scale of the current 

base map. Note: topo24k is currently implemented in the MBS user interface only (see user).
Table 5 13

Table 5. Map parameters and actions.—Continued

Parameter Arguments Description

eez 1 Displays Exclusive Economic Zone boundaries (USA only). The settings: eez=off (the default) 

hides the boundaries; eez=on displays the boundaries; eez=auto displays the boundaries only 

if they can be resolved at the scale of the current base map.

nms 1 Displays National Marine Sanctuary and Marine National Monument boundaries (USA only). 

The settings: nms=off (the default) hides the boundaries; nms=on displays the boundaries; 

nms=auto displays the boundaries only if they can be resolved at the scale of the current base 

map.

opdlm 1 Displays Minerals Management Service (MMS) Official Protraction Diagram and Leasing Map 

outlines (offshore USA only). The settings: opdlm=off (the default) hides the outlines; 

opdlm=on displays the outlines; opdlm=auto displays the outlines only if they can be resolved at the scale of the current base map.

hucs 1 Displays USGS hydrologic unit (watershed) boundaries (USA only). The settings: huc=off (the 

default) hides the boundaries; huc=on displays the boundaries; huc=auto displays the boundaries only if they can be resolved at the scale of the current base map.

grid 1 Displays latitude and longitude grid lines. The settings: grid=off (the default) hides the grid 

lines; grid=on displays the grid lines; grid=auto displays the grid lines only if they can be 

resolved at the scale of the current base map.

river 1 Displays rivers. The settings: river=off (the default) hides rivers; river=on displays rivers; 

river=auto displays rivers only if they can be resolved at the scale of the current base map.

lake 1 Displays lakes. The settings: lake=off hides lakes; lake=on displays lakes; lake=auto (the 

default) displays lakes only if they can be resolved at the scale of the current base map.

1 For more information about Generic Mapping Tools (GMT) map parameters, see http://gmt.soest.hawaii.edu/gmt/doc/gmt/html/GMT_Docs/node1.html.
Prepared by the Pembroke Publishing Service Center.

For more information concerning this report, contact:

Director

U.S. Geological Survey

Woods Hole Coastal and Marine Science Center

384 Woods Hole Road

Quissett Campus

Woods Hole, MA 02543-1598

wbarnhardt@usgs.gov

508-548-8700 or 508-457-2200

or visit our Web site at:

http://woodshole.er.usgs.gov/
Linck and others—Constructing Uniform Resource Locators (URLs) for Searching the Marine Realms Information Bank—Open-File Report 2009–1266

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