Volcanic basement topography (contours)

Metadata:

• Identification_Information
• Metadata_Reference_Information
• Data_Quality_Information
• Entity_and_Attribute_Information
• Distribution_Information
• Spatial_Data_Organization_Information
• Spatial_Reference_Information
• Lineage

Identification_Information:

Point_of_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

Water & Environmental Research Institute (WERI), University of Guam

Contact_Position: Staff Hydrologist

Contact_Voice_Telephone: +1-671-735-2693

Citation:

Citation_Information:

Originator:

Vann, D.T., V.M. Bendixson, D.F. Roff, N.C. Habana, C.A. Simard, R.M. Schumann, and J.W. Jenson

Publication_Date: 2013

Title: Volcanic basement topography (contours)

Online_Linkage: <http://www.weriguam.org/reports/list.html>

Other_Citation_Details:

Dataset is either part of or derived from the basement volcanic map titled "Topography of the Basement Rock beneath the Northern Guam Lens Aquifer and its Implications for Groundwater Explorartion and Development"

Keywords:

Theme:

Theme_Keyword: topography

Theme_Keyword: volcanic basement

Theme_Keyword: Northern Guam Lens Aquifer

Theme_Keyword: NGLA

Theme_Keyword: groundwater

Theme_Keyword: hydrogeology

Theme_Keyword: contours

Place:

Place_Keyword: Guam

Place_Keyword: U.S. Territory

Place_Keyword: Mariana Islands

Place_Keyword: Micronesia

Place_Keyword: Northwest Pacific

Place_Keyword: Western Pacific

Place_Keyword: Pacific Islands

Description:

Abstract:

This dataset is part of the 2013 volcanic basement map, an update of the original 1982 map produced by the Northern Guam Lens Study (CDM, 1982). The work on updating the map utilized geophysical and drilling data to correct and refine our understanding of basement topography and improve the map; see WERI Technical Report #141 (Bendixson, 2013). Details on the methodology used, content, and applications of the map can be found in WERI Technical Report #142 (Vann et al., 2013).

Purpose:

This dataset shows the elevation contours of the contact surface between the basement volcanic units and the overlying limestone units of the northern Guam plateau. The basement topography is highly significant because it guides the movement of groundwater and separates the NGLA into subsurface drainage basins.

Supplemental_Information:

Because permeability of the underlying volcanic basement rock is orders magnitude lower than that of the limestone bedrock aquifer that overlies it, the uneven topography of the basement partitions northern Guam’s aquifer into six semi-contiguous basins, each containing three groundwater zones. In the basal zone, the freshwater lens flows seaward, floating on saltwater that permeates the aquifer beneath it. Para-basal water overlies the basement rock below sea level in a zone extending from the basement sea-level contour down to the saltwater toe, past which it enters the basal zone. Patches of supra-basal water overlie parts of the flank of basement rock above sea level, where vadose water flowing downslope toward the para-basal zone may be concentrated or impounded behind topographic irregularities.

Status:

Progress: In work

Maintenance_and_Update_Frequency: As needed

Use_Constraints:

This dataset is for general information and educational purposes only and not for use in litigation. It contains no authoritative positional or other data. The Water & Environmental Research Institute (WERI) cannot assume liability for any damages or misrepresentations caused by any inaccuracies in the data or as a result of the data to be in a particular system.

Data_Set_Credit: Vann et al. (2013)

Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 2013

Currentness_Reference: publication date

Metadata_Reference_Information:

Metadata_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Maria Kottermair

Contact_Organization: Water & Environmental Research Institute, University of Guam

Contact_Position: Research Assistant III

Contact_Electronic_Mail_Address: mariakottermair@uguamlive.uog.edu

Contact_Voice_Telephone: (671) 735-2751

Metadata_Date: 20131015

Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata

Data_Quality_Information:

Lineage:

Source_Information:

Source_Citation:

Citation_Information:

Originator: WERI

Title: 121812A_contours

Geospatial_Data_Presentation_Form: shapefile

Source_Information:

Source_Citation:

Citation_Information:

Title: head_nopump

Originator: USGS

Geospatial_Data_Presentation_Form: TIN

Other_Citation_Details: Draft results from model by Steven Gingerich (USGS)

Logical_Consistency_Report:

see WERI Technical Reports #141 by Bendixson (2013) and #142 by Vann et al. (2013) for detailed information.

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: basement_topography_contours

Attribute:

Attribute_Label: OBJECTID

Attribute_Definition: Internal feature number.

Attribute_Definition_Source: Esri

Attribute_Domain_Values:

Unrepresentable_Domain:

Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute_Label: Shape

Attribute_Definition: Feature geometry.

Attribute_Definition_Source: Esri

Attribute_Domain_Values:

Unrepresentable_Domain: Coordinates defining the features.

Attribute:

Attribute_Label: ID

Attribute:

Attribute_Label: Contour_m

Attribute:

Attribute_Label: Shape_Length

Attribute_Definition: Length of feature in internal units.

Attribute_Definition_Source: Esri

Attribute_Domain_Values:

Unrepresentable_Domain: Positive real numbers that are automatically generated.

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Water & Environmental Research Institute, University of Guam

Spatial_Data_Organization_Information:

Point_and_Vector_Object_Information:

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Geodetic_Model:

Horizontal_Datum_Name: D_WGS_1984

Ellipsoid_Name: WGS_1984

Lineage: