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Methane in coastal sea water, sea ice, and bottom sediments, Beaufort Sea, Alaska

Metadata also available as - [Questions & Answers] - [Parseable text] - [DIF]

Metadata:

Identification_Information
Data_Quality_Information
Spatial_Data_Organization_Information
Spatial_Reference_Information
Entity_and_Attribute_Information
Distribution_Information
Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: Lorenson, Thomas D.

Originator: Kvenvolden, Keith A.

Publication_Date: 1995

Title:

Methane in coastal sea water, sea ice, and bottom sediments, Beaufort Sea, Alaska

Edition: 1

Geospatial_Data_Presentation_Form: map

Series_Information:

Series_Name: U.S. Geological Survey Open-File Report
Issue_Identification: 95-70

Publication_Information:

Publication_Place: Menlo Park, CA
Publisher: U.S. Geological Survey

Online_Linkage: <http://pubs.usgs.gov/of/1995/of95-070/>

Description:

Abstract:: This report summarizes data acquired from 1990 to 1994 for the gas-hydrate portion of the USGS project "Permafrost and gas hydrate as possible sources of methane" of the USGS Global Change and Climate History program. The objective of this project has been to test the hypothesis that gas hydrate deposits of the Beaufort Sea continental shelf are destabilized by the ~10°C temperature increase that has resulted from the Holocene transgression of the Arctic Ocean. To test this idea we have selected an area off the north coast of Alaska centered on Harrison Bay. We have measured the concentration of methane in surficial sediments, in the water column when ice is present and absent, and in seasonal sea ice. Our results show that more methane is present in the water when ice is present than when ice is absent, and that methane is also present within the ice itself, often at higher concentrations than in the water. Thus the Beaufort Sea shelf of Alaska is a seasonal source of methane. The primary source of this methane has not yet been defined, but gas hydrate is a reasonable candidate.
Purpose:: The objective of this project has been to test the hypothesis that gas hydrate deposits of the Beaufort Sea continental shelf are destabilized by the ~10°C temperature increase that has resulted from the Holocene transgression of the Arctic Ocean.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 19920501
Ending_Date: 19940826

Currentness_Reference:

The surveys were undertaken during the last week of April and first week of May 1992, the middle of April 1993, the latter portion of April 1994, the second week of September 1993, and the later portion of August 1994.

Status:

Progress: Complete
Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -152.20717
East_Bounding_Coordinate: -144.99833
North_Bounding_Coordinate: 72.64800
South_Bounding_Coordinate: 70.05267

Keywords:

Theme:

Theme_Keyword_Thesaurus: none
Theme_Keyword: methane
Theme_Keyword: gas hydrate
Theme_Keyword: petroleum
Theme_Keyword: sea ice
Theme_Keyword: sea water

Place:

Place_Keyword_Thesaurus: None
Place_Keyword: Beaufort Sea
Place_Keyword: Alaska
Place_Keyword: AK

Theme:

Theme_Keyword_Thesaurus: National Geologic Map Database Catalog themes, augmented
Theme_Keyword: 1300 - Marine Geology
Theme_Keyword: 1900 - Geochemistry

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Categories
Theme_Keyword: geoscientificInformation

Place:

Place_Keyword_Thesaurus: Augmented FIPS 10-4 and FIPS 6-4, version 1.0
Place_Keyword: 02185 = North Slope
Place_Keyword: OC10 = Arctic

Access_Constraints: none

Use_Constraints: none

Point_of_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Thomas D. Lorenson
Contact_Organization: Branch of Pacific Marine Geology

Contact_Address:

Address_Type: mailing address
Address:: Mail Stop 999
U.S. Geological Survey
345 Middlefield Road
City: Menlo Park
State_or_Province: CA
Postal_Code: 94025

Contact_Voice_Telephone: (415) 354-3094

Contact_Facsimile_Telephone: (415) 354-3191

Contact_Electronic_Mail_Address: lorenson@octopus.wr.usgs.gov

Browse_Graphic:

Browse_Graphic_File_Name: <http://pubs.usgs.gov/of/1995/of95-070/core/meta/figure2.gif>
Browse_Graphic_File_Description:: The study area showing six north-south transects with the water and ice station locations.
Browse_Graphic_File_Type: GIF

Data_Set_Credit:

The project has been conducted in collaboration with the University of Washington and the University of Hawaii. We thank (1) M.D. Lilley, E.J. Olson, and E. McLaughlin, School of Oceanography, University of Washington, for the information on methane concentrations, methane oxidation rates, and nutrient concentrations in seawater; (2) B.N. Popp, F. J. Sansone, and T. Rust, SOEST, University of Hawaii, for the isotopic analyses of methane. We are grateful to (1) P.W. Barnes, U.S. Geological Survey, for guidence in Arctic operations, and (2) E. Reimnitz for help in collecting sediment samples for gas analyses. This work is supported by the USGS Global Change and Climate History Program.

Native_Data_Set_Environment: Macintosh

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report:: See process descriptions for analytical methods. For more information about attribute accuracy, users are urged to contact the authors.

Logical_Consistency_Report:

CTD (conductivity, temperature, depth) casts were made at each station. CTD data was recorded internally by a Seacat 19 CTD probe made by Sea Bird of Seattle Washington. The data was downloaded onto a computer where it was processed using Seasoft Version 4.016. The sub-programs LOOPEDIT, BINAVE, then DERIVE were utilized to process the raw data. The data were averaged into 0.5m intervals. The upcast and downcast were evaluated, and only one cast is plotted. In general the upcast was used because the sensors showed less fluctuation.

Completeness_Report:

Methane oxidation rate is given only for samples collected in 1992 and 1993. Isotopic compositions are given only for samples collected in 1994. Nutrients are given only for samples collected in 1992.

Lineage:

Process_Step:

Process_Description:: Measurements of sea water. In our survey, we measured methane concentration in sea water under the ice on six primary transects from nearshore to the shelf break at water depths ranging from 2.5 to 88m from Cape Halkett east to Mikkelsen Bay, Alaska. Other surface water samples were taken at various locations where water depths ranged from 2 to 20m within the area between Camden Bay and the Colville River Delta. One oceanic surface water sample was also collected in April 1993 at 72° 38' N. latitude . The surveys were undertaken during the last week of April and first week of May 1992, the middle of April 1993, the latter portion of April 1994, the second week of September 1993, and the later portion of August 1994. At each station in April and May, a 23- cm diameter hole was drilled through the 2-m thick first-year ice. Niskin bottles (1.7 l) were attached at intervals to a line lowered to the seafloor and subsequently tripped to collect water samples for methane determinations. In September 1993 and August 1994, when no ice was present, a boat was used to transit to stations. As each Niskin bottle was recovered, 100 cm3 of water was transferred to a 140 cm3 syringe. A heat lamp to prevent the water from freezing during April and May surveys. In the laboratory at the end of each day's field work, 40 cm3 of ultra-pure nitrogen were added to each of the syringes, and methane was extracted from the water into the nitrogen at room temperature by shaking the syringe, following a method modified from McAullife (1971). A portion of the resulting gas mixture was measured for methane content by gas chromatography. Multiple extractions were used on several samples to determine an empirical extraction efficiency coefficient which was utilized with the remainder of the samples that were extracted only once. Our analyzed gas standard contained 10 ppm ±2% methane in nitrogen. Duplicate samples were analyzed for each water depth with an average standard deviation of ±0.6nM.
CTD (conductivity, temperature, depth) casts were made at each station. CTD data was recorded internally by a Seacat 19 CTD probe made by Sea Bird of Seattle Washington. The data was downloaded onto a computer where it was processed using Seasoft Version 4.016. The sub-programs LOOPEDIT, BINAVE, then DERIVE were utilized to process the raw data. The data were averaged into 0.5m intervals. The upcast and downcast were evaluated, and only one cast is plotted. In general the upcast was used because the sensors showed less fluctuation.
The methods utilized to measure nutrients in this study were adapted from older colorimetric procedures and are described in detail by Whitledge and others, (1981). A basic description of each method, conducted on a Technicon Autoanalyzer System, follows. Phosphate is determined as phosphomolybdic acid which in its reduced form in the presence of antimony has an absorption maximum at 880 nm. The method is basically an automated version of the procedure of Murphy and Riley (1962).
Orthosilicic acid is determined by its reaction with molybdate in aqueous acidic solution to form silicomolybdic acid. In this procedure, which is basically that of Armstrong and others, (1967), stannous chloride is used to reduce silicomolybdic acid to the heteropolic acid which has an absorption maximum at 820 nm.
Nitrite is determined by the Greiss reaction in which sulfanilamide and N-(1-Napthyl)ethylenediamine dihydrochloride react with nitrite in aqueous acidic solution to form an intensely pink diazo dye with an absorption maximum at 540 nm (Bendschneider and Robinson, 1952). Nitrate, after it is reduced to nitrite by passage through a column of copperized cadmium filings, is determined in an identical manner to nitrite (Wood and others 1967). This analysis gives the sum of nitrate + nitrite, and nitrate is determined by difference.
Ammonium is determined by the Berthelot reaction in which hypochlorous acid and phenol react with ammonium in aqueous alkaline solution to form indophenol blue, an intensely blue chromophore with an absorption maximum at 637 nm. The method utilized is a modification of the procedure reported by Slawyk and MacIsaac (1972).
Process_Date: 1994

Process_Step:

Process_Description:: Measurements of sea ice. The methane content of sea ice was measured at 51 stations in 1993 and 1994. A 1m long by 7.6 cm diameter ice corer with an extension was used to core through the ice to sea water. The ice core was laid out on the sea ice, measured and cut into 10 cm sections. Selected intervals were chosen, then placed in 1-liter friction sealed cans equipped with 2 septa ports, sealed, and kept frozen. At the field laboratory, each sample was weighed, then the headspace within the can was purged with ultra pure nitrogen for 5 minutes at flow rates exceeding 200 ml/min. Tests on the methane content of the purged headspace with the frozen ice core inside yielded concentrations less than 0.1 ppm. The cans containing ice samples were placed in hot water baths and stabilized at approximately 20°C. Each can was shaken by hand for about 30 seconds to partition the dissolved methane between the water and the nitrogen headspace. Next, a syringe containing 30 ml of ultra pure grade nitrogen was injected into the can, then 30 ml of the resulting mixture of headspace and gas was removed and analyzed for methane content in the same manner as described for sea water samples. The volume of headspace in the can was determined by the weight of the ice sample, assuming that once melted the water occupied a volume of 1 ml/gm.
Process_Date: 1994

Process_Step:

Process_Description:: Measurements of sea-floor sediment. Sediment samples were taken in May 1992 operating from the ice canopy. A hole was augured in the ice, through which a 45 x 7.5 cm core barrel with an auger cutting head was lowered. The core barrel was attached to 1.5-m long connecting stems in series up to a maximum length of 15.5 m. Once on the ocean bottom, the core barrel was rotated by hand with the aid of a T-bar until no further penetration was achieved. Upon retrieval, the liner containing sediment was extruded onto the ice. The least disturbed 10-cm long (a volume of about 450 ml wet sediment) section of the core was chosen and placed in a septa-equipped 1-liter sample can. Seawater was added to the brim of the can, then 200 ml of water was removed, creating a 200 ml headspace. About 2-3 grams of sodium azide was added as a biocide. The can was sealed, then purged with helium at a flow rate estimated to be greater then 300 ml/min for 5 minutes. The samples were kept frozen until analysis at our Menlo Park laboratories.
Process_Date: 199205

Process_Step:

Process_Description:

Measurements of methane isotopic composition. A limited number of measurements of the carbon isotopic composition of methane were made at the University of Hawaii. The results reveal a wide range of values from -31.1 to -80.5 o/oo.

Process_Date: 1995

Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Brian N. Popp

Contact_Address:

Address_Type: mailing address
Address:: 2525 Correa Road, HIG 415
University of Hawai`i-Manoa
City: Honolulu
State_or_Province: HI
Postal_Code: 96822
Country: USA

Contact_Voice_Telephone: (808) 956-6206

Contact_Facsimile_Telephone: (808) 956-2538

Contact_Electronic_Mail_Address: popp@kiawe.soest.hawaii.edu

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Point

Point_and_Vector_Object_Information:

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: Entity Point
Point_and_Vector_Object_Count: 88

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Geographic:

Latitude_Resolution: 0.00016667
Longitude_Resolution: 0.00016667
Geographic_Coordinate_Units: Decimal degrees

Vertical_Coordinate_System_Definition:

Depth_System_Definition:

Depth_Datum_Name: mean sea-level
Depth_Resolution: 1
Depth_Distance_Units: meters
Depth_Encoding_Method: Attribute values

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: water sample
Entity_Type_Definition_Source: USGS OFR 95-70

Attribute:

Attribute_Label: Station
Attribute_Definition:: Identifier for the sample locality, composed as YYMsssR where YY is the last two digits of the year, M is the month (no samples were taken from October through December, thus one digit suffices), sss is the site number, and R (literally) is present to indicate that the site was occupied at an earlier date.
Attribute_Definition_Source: USGS OFR 95-70

Attribute:

Attribute_Label: Latitude

Attribute_Definition: North latitude of the sample locality.

Attribute_Definition_Source: FIPS 70-1

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0
Range_Domain_Maximum: 90
Attribute_Units_of_Measure: decimal degrees
Attribute_Measurement_Resolution: 0.00016667

Attribute:

Attribute_Label: Longitude

Attribute_Definition:

Longitude of the sample locality. Negative values are measured westward from the Prime Meridian, positive values are measured eastward from the Prime Meridian.

Attribute_Definition_Source: FIPS 70-1

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0
Range_Domain_Maximum: 180
Attribute_Units_of_Measure: decimal degrees
Attribute_Measurement_Resolution: 0.00016667

Attribute:

Attribute_Label: Date

Attribute_Definition:

Calendar date when sample was collected, expressed as a FIPS date using the form YYYYMMDD where YYYY signifies the year, MM the month, and DD the day (month and day beginning with 1).

Attribute_Definition_Source: FIPS 4-1

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 19920501
Range_Domain_Maximum: 19940824
Attribute_Units_of_Measure: Calendar days
Attribute_Measurement_Resolution: 1

Attribute:

Attribute_Label: Sample depth (m)

Attribute_Definition:

Depth in meters at which water was sampled, measured from sea-surface.

Attribute_Definition_Source: USGS OFR 95-70

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0
Range_Domain_Maximum: 88
Attribute_Units_of_Measure: meters
Attribute_Measurement_Resolution: 0.5

Attribute:

Attribute_Label: Methane (nM)

Attribute_Definition: Dissolved methane concentration in the water.

Attribute_Definition_Source: USGS OFR 95-70

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0
Range_Domain_Maximum: 275
Attribute_Units_of_Measure: nM
Attribute_Measurement_Resolution: 0.1

Attribute:

Attribute_Label: Methane Isotopic Composition (ppt)

Attribute_Definition:

Carbon isotopic composition (delta-13C) relative to PDB

Attribute_Definition_Source: USGS OFR 95-70

Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: -80.5
Range_Domain_Maximum: -31.1
Attribute_Units_of_Measure: Parts per thousand by weight
Attribute_Measurement_Resolution: 0.1

Attribute:

Attribute_Label: Methane Specific Oxidation

Attribute_Definition:

Rate of microbial oxidation of methane. This "specific oxidation rate" is really just the first order rate constant for methane uptake and has the units (1/day) because the oxidation rate (nM/day) is divided by the concentration (nM).

Attribute_Definition_Source: USGS OFR 95-70

Attribute_Domain_Values:

Range_Domain:

Attribute_Units_of_Measure: 1/day

Attribute:

Attribute_Label: Methane Oxidation Rate (nM/day)

Attribute_Definition:

The first order rate constant for the microbial oxidation of methane.
We measure methane oxidation by first removing (via shaking) most of the methane from the collected samples. We then spike the samples with a known amount of labeled methane which is somewhere near the concentration of methane in the natural sample. We measure the rate of methane oxidation by watching labeled carbon dioxide grow in. Some methane is converted to biomass and we get at this part by filtering and counting the amount of labeled particulate carbon.
Once we have these numbers, we calculate what is called the "specific oxidation rate". This is simply the measured rate divided by the concentration of methane in the incubation vials. This "specific oxidation rate" is really just the first order rate constant for methane uptake and has the units (1/day) because the oxidation rate (nM/day) is divided by the concentration (nM).
We can then derive what we call the "ambient oxidation rate" by multipling the "specific oxidation rate" by the concentration of methane actually measured in the samples. This obviously only works if first order kinetics are followed but we have found this to be the case in all of the environments we have studied.

Attribute_Definition_Source: USGS OFR 95-70

Attribute_Domain_Values:

Range_Domain:

Attribute_Units_of_Measure: nM per day

Attribute:

Attribute_Label: Comments
Attribute_Definition:: Descriptive information about the water samples or the analyses of them.
Attribute_Definition_Source: USGS OFR 95-70

Attribute:

Attribute_Label: PO4
Attribute_Definition: Phosphate concentration in water samples.
Attribute_Definition_Source:: Phosphate is determined as phosphomolybdic acid which in its reduced form in the presence of antimony has an absorption maximum at 880 nm. The method is basically an automated version of the procedure of Murphy and Riley (1962).

Attribute:

Attribute_Label: Si
Attribute_Definition: Silica concentration in water sample.
Attribute_Definition_Source:: Orthosilicic acid is determined by its reaction with molybdate in aqueous acidic solution to form silicomolybdic acid.
In this procedure, which is basically that of Armstrong and others, (1967), stannous chloride is used to reduce silicomolybdic acid to the heteropolic acid which has an absorption maximum at 820 nm.

Attribute:

Attribute_Label: NO3
Attribute_Definition: Nitrate concentration in water samples.
Attribute_Definition_Source:: Nitrate, after it is reduced to nitrite by passage through a column of copperized cadmium filings, is determined in an identical manner to nitrite (Wood and others 1967). This analysis gives the sum of nitrate + nitrite, and nitrate is determined by difference.

Attribute:

Attribute_Label: NO2
Attribute_Definition_Source:: Nitrite is determined by the Greiss reaction in which sulfanilamide and N-(1-Napthyl)ethylenediamine dihydrochloride react with nitrite in aqueous acidic solution to form an intensely pink diazo dye with an absorption maximum at 540 nm (Bendschneider and Robinson, 1952).

Attribute:

Attribute_Label: NH4
Attribute_Definition: Ammonium concentration in water samples.
Attribute_Definition_Source:: Ammonium is determined by the Berthelot reaction in which hypochlorous acid and phenol react with ammonium in aqueous alkaline solution to form indophenol blue, an intensely blue chromophore with an absorption maximum at 637 nm. The method utilized is a modification of the procedure reported by Slawyk and MacIsaac (1972).

Detailed_Description:

Entity_Type:

Entity_Type_Label: CTD cast
Entity_Type_Definition_Source: USGS OFR 95-70

Attribute:

Attribute_Label: Temperature

Attribute_Definition: In situ water temperature.

Attribute_Definition_Source:

Attribute_Domain_Values:

Range_Domain:

Attribute_Units_of_Measure: degrees Celsius

Attribute:

Attribute_Label: Salinity

Attribute_Definition:

Salinity of the water as determined from the conductivity measurements recorded by the CTD instrument.

Attribute_Definition_Source:

Attribute_Domain_Values:

Range_Domain:

Attribute_Units_of_Measure: Parts per thousand by weight

Attribute:

Attribute_Label: Depth

Attribute_Definition:

Depth of the CTD instrument when temperature and conductivity were recorded. This parameter is derived internally by the CTD instrument by using ambient hydrostatic pressure.

Attribute_Definition_Source:

Attribute_Domain_Values:

Range_Domain:

Attribute_Units_of_Measure: meters

Attribute:

Attribute_Label: Conductivity
Attribute_Definition:: Conductivity of water as determined by the CTD instrument.
Attribute_Definition_Source:: CTD (conductivity, temperature, depth) casts were made at each station. CTD data was recorded internally by a Seacat 19 CTD probe made by Sea Bird of Seattle Washington. The data was downloaded onto a computer where it was processed using Seasoft Version 4.016. The sub-programs LOOPEDIT, BINAVE, then DERIVE were utilized to process the raw data.

Detailed_Description:

Entity_Type:

Entity_Type_Label: ice sample
Entity_Type_Definition_Source: USGS OFR 95-70

Attribute:

Attribute_Label: Core interval (cm)

Attribute_Definition:

The length of the part of the ice core that was analyzed.

Attribute_Definition_Source: USGS OFR 95-70

Attribute_Domain_Values:

Range_Domain:

Attribute_Units_of_Measure: centimeters

Attribute:

Attribute_Label: Can Wt. gm

Attribute_Definition:

Weight in grams of the container before placing the sample into it.

Attribute_Definition_Source: USGS OFR 95-70

Attribute_Domain_Values:

Range_Domain:

Attribute_Units_of_Measure: grams

Attribute:

Attribute_Label: Can+sample Wt. gm

Attribute_Definition: Weight in grams of the sample with the container.

Attribute_Definition_Source: USGS OFR 95-70

Attribute_Domain_Values:

Range_Domain:

Attribute_Units_of_Measure: grams

Attribute:

Attribute_Label: Sample Wt. gm

Attribute_Definition:

Difference between variable "Can+sample Wt. gm" and variable "Can Wt. gm".

Attribute_Definition_Source: USGS OFR 95-70

Attribute_Domain_Values:

Range_Domain:

Attribute_Units_of_Measure: grams

Attribute:

Attribute_Label: Headspace Liters

Attribute_Definition_Source: USGS OFR 95-70

Attribute_Domain_Values:

Range_Domain:

Attribute_Units_of_Measure: liters

Attribute:

Attribute_Label: Methane ppm

Attribute_Definition:

Concentration of methane in the ice-core sample, as a proportion of the weight of the sample.

Attribute_Definition_Source: USGS OFR 95-70

Attribute_Domain_Values:

Range_Domain:

Attribute_Units_of_Measure: pars per million by weight

Attribute:

Attribute_Label: Methane (nM)

Attribute_Definition:

Concentration of methane in the ice-core sample, in absolute rather than relative terms.

Attribute_Definition_Source: USGS OFR 95-70

Attribute_Domain_Values:

Range_Domain:

Attribute_Units_of_Measure: nM

Attribute:

Attribute_Label: Carbon Isotopic Composition (ppt)

Attribute_Definition:

Carbon isotopic composition of the methane in the ice- core sample (delta-13C) relative to PDB

Attribute_Definition_Source: USGS OFR 95-70

Attribute_Domain_Values:

Range_Domain:

Attribute_Units_of_Measure: Parts per thousand relative to the PDB standard.

Attribute:

Attribute_Label: Carbon Isotopic Composition (ppt) duplicate

Attribute_Definition: same as Carbon Isotopic Composition (ppt)

Attribute_Definition_Source: USGS OFR 95-70

Attribute_Domain_Values:

Range_Domain:

Attribute_Units_of_Measure: Parts per thousand relative to the PDB standard.

Attribute:

Attribute_Label: Description
Attribute_Definition: Textual description of the locality.
Attribute_Definition_Source: USGS OFR 95-70

Detailed_Description:

Entity_Type:

Entity_Type_Label: sediment sample
Entity_Type_Definition_Source: USGS OFR 95-70

Attribute:

Attribute_Label: Top (of sampled interval in core)

Attribute_Definition:

Distance from top of sediment core to top of the sampled interval.

Attribute_Definition_Source: USGS OFR 95-70

Attribute_Domain_Values:

Range_Domain:

Attribute_Units_of_Measure: centimeters

Attribute:

Attribute_Label: Bottom (of sampled interval in core)
Attribute_Definition:: Distance from top of sediment core to bottom of the sampled interval.
Attribute_Definition_Source: USGS OFR 95-70

Attribute:

Attribute_Label: Lithology
Attribute_Definition: Short description of the sediment.
Attribute_Definition_Source: USGS OFR 95-70

Attribute:

Attribute_Label: Methane (uL/L wet sediment)

Attribute_Definition:

Concentration of methane in the sediment as a proportion of the volume of the wet sediment.

Attribute_Definition_Source: USGS OFR 95-70

Attribute_Domain_Values:

Range_Domain:

Attribute_Units_of_Measure: microliters of methane per liter of wet sediment

Distribution_Information:

Distributor:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Peter N. Schweitzer

Contact_Address:

Address_Type: mailing address
Address:: Mail Stop 918 National Center
U.S. Geological Survey
12201 Sunrise Valley Drive
City: Reston
State_or_Province: VA
Postal_Code: 20192
Country: USA

Contact_Voice_Telephone: (703) 648-6533

Contact_Facsimile_Telephone: (703) 648-6560

Contact_Electronic_Mail_Address: pschweitzer@usgs.gov

Resource_Description: U.S. Geological Survey Open-File Report 95-70

Distribution_Liability:

This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards (or with the North American Stratigraphic Code). Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Standard_Order_Process: