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PRINCIPAL INVESTIGATOR: KEYWORDS: lake, limnology, pH, hydrogen ion, chemistry
ABSTRACT: As part of the McMurdo Long Term Ecological Research (LTER)
project in the Dry Valleys of Antarctica, hydrogen ion concentrations were
monitored in various lakes of the region. An Orion portable pH meter was used to
record hydrogen ion concentrations at depth specific intervals in perennial
ice-covered lakes.
VARIABLES: limno run, location name, location code, date, depth (m), pH,
pH comments, file name
RESEARCH LOCATION: Samples were collected from limnological sampling stations located
in the McMurdo Dry Valleys of Antarctica. Regularly monitored sites include East Lake Bonney, West
Lake Bonney, Lake Hoare and Lake Fryxell. In addition, measurements were obtained from Don Juan & Dirty
Little Hoare Ponds, Lake Garwood, Lake Joyce, Lake Miers and Lake Vanda. Descriptions of all
of these lakes can be found in the
McMurdo Dry Valley Lake Descriptions file.
METHODS: Lake water samples were collected at specific depths with a five-liter Niskin
bottle during normal LTER limnological sampling. Sub-samples for pH analysis were decanted into 20 mL
scintillation vials. A portable Beckman psi 10 with a combination pH electrode was used to record
hydrogen ion concentration and temperature of each sample. The meter and probe were double endpoint
calibrated with pH 7 and pH 4 buffers. The probe was manually agitated by slowly moving in an up and
down motion (~1 cm). Once the probe stabilized, the data was recorded.
TIMING: Samples were collected from the following sites and dates: CITATIONS:
COMMENTS:
STATUS: Public Access (Type 1).
VARIABLE DESCRIPTION:
VARIABLE TYPE DESCRIPTION UNITS MISSING VALUE INDICATOR MINIMUM MAXIMUM PRECISION Limno Run Text Code for lake's sampling location and date none Required entry n/a n/a n/a Location Name Text Name of lake where measurement was made none Required entry n/a n/a n/a Location Code Text Code for site where measurement was made none Required entry n/a n/a n/a Date Date Date on which sample was gathered mm/dd/yy Required entry 01/01/93 12/31/99 dd Depth (m) Number Distance below ice from which sample was drawn meters Required entry 1 80 1 pH Number hydrogen ion concentration found at lake depth negative power to which 10 must be raised to describe the molar concentration (mol/liter) of H+ Null 0 10 0.01 pH Comments Text Helpful hints about the pH sample Null n/a n/a n/a File Name Text Name of file in which data was submitted Null n/a n/a n/a LOG: Data from this table was submitted to INSTAAR by the MCM LTER limnology team based
out of Montana State University and the University of Alabama. The 1993-94, 1994-95, 1995-96,
1996-97 and 1997-98 data was submitted by Kathy Welch at the University of Alabama. 1996-97 and 1997-98 data
was also submitted by Craig Wolf at Montana State University. Since there was some overlap between
these files, the records from Montana State University were used. Only two of the records in the pH9697.txt
file (from Kathy Welch at the University of Alabama) were added to this dataset since they were not in
the files from Montana. The raw data files listed under 'file name' are the names of the
original ascii text files used.
Upon arrival at INSTAAR, the data manager fine-tuned the location codes and limno runs to
match those provided in the "locations, dates, codes for lake chemistry, biology samples"
file. The file was imported into Microsoft Access on INSTAAR's Unix system,
and can currently be found there. The file was then exported in ascii, comma delimited
text and MS-DOS text (table layout) to present on the MCM LTER web site. Both of these files are
linked to this web page above.
Information for the metadata was submitted by Craig Wolf at Montana State University in
the MetapH9697.rtf file. The file was called up using Microsoft Word version 6.0,
allowing its text to be used to create this page in html format.
NOTE: Data contained in these files has been subjected to quality
control standards imposed by the investigator. The user of this data
should be aware that, while efforts have been taken to ensure that these
data are of the highest quality, there is no guarantee of perfection
for the data contained herein and the possibility of errors exists. If
you encounter questionable data, please contact the MCM LTER data manager
(; (303)492-4639) so that the data can be
corrected or qualified. Thus, these data may be modified and future
data will be appended.
Season East Bonney West Bonney Hoare Fryxell
1993-1994 27-Oct-1993 29-Oct-1993 5-Nov-1993 16-Nov-1993
24-Nov-1993 26-Nov-1993 1-Dec-1993 7-Dec-1993
21-Dec-1993 9-Dec-1993 30-Dec-1993 7-Jan-1994
23-Dec-1993 19-Jan-1994 18-Jan-1994
1994-1995 2-Nov-1994 5-Nov-1994 10-Nov-1994 14-Nov-1994
23-Nov-1994 25-Nov-1994 30-Nov-1994 4-Dec-1994
17-Dec-1994 19-Dec-1994 24-Dec-1994 30-Dec-1994
10-Jan-1995 12-Jan-1995 21-Jan-1995 17-Jan-1995
1995-1996 19-Sep-1995 21-Sep-1995 7-Sep-1995 14-Sep-1995
6-Oct-1995 4-Oct-1995 25-Sep-1995 28-Sep-1995
17-Oct-1995 19-Oct-1995 10-Oct-1995 14-Oct-1995
2-Dec-1995 5-Dec-1995 21-Nov-1995 26-Nov-1995
1-Jan-1996 4-Jan-1996 23-Dec-1995 27-Dec-1995
1996-1997 3-Nov-1996 1-Nov-1996 8-Nov-1996 26-Oct-1996
24-Nov-1996 27-Nov-1996 2-Dec-1996 19-Nov-1996
15-Jan-1997 17-Jan-1997 12-Jan-1997 9-Jan-1997
1997-1998 8-Nov-1997 11-Nov-1997 15-Nov-1997 18-Nov-1997
14-Dec-1997 16-Dec-1997
20-Dec-1997 22-Dec-1997 26-Dec-1997 29-Dec-1997
1998-1999 9-Nov-1998 11-Nov-1998 3-Nov-1998 28-Oct-1998
6-Dec-1998 9-Dec-1998 1-Dec-1998 23-Nov-1998
30-Dec-1998 1-Jan-1999 26-Dec-1998 20-Dec-1998
1999-2000 6-Nov-1999 11-Nov-1999 17-Nov-1999 30-Oct-1999
3-Dec-1999 5-Dec-1999 12-Dec-1999 27-Nov-1999
28-Dec-1999 30-Dec-1999 4-Jan-2000 23-Dec-1999
&
Season Don Juan Pond Dirty Little Garwood Joyce Miers Vanda
Hoare Pond
1994-1995 24-Jan-1995 25-Jan-1995 1-Dec-1994
1995-1996 8-Jan-1996
1996-1997 27-Jan-1997 5-Dec-1996 10-Dec-1996
1997-1998 9-Dec-1997 5-Dec-1997
none
none