This data release contains supplementary material to the Geochemistry, Geophysics, Geosystems article:
"Modeling ash dispersal from future eruptions of Taupo supervolcano", by S.J. Barker et al.
This paper uses Ash3d model simulations to calculate the probability of a given tephra-fall thickness from eruptions of the following sizes: 0.1km3, 1 km3, 5 km3, 50 km3, and 500 km3. All volume cases were modeled with umbrella cloud formation, with additional Ash3d simulations for the case of a 0.1 km3 eruption assuming no development of an umbrella cloud. One thousand model simulations were run for each of these cases. The data release contains model outputs from each of the simulations. The results are packaged in separate zip files, one for each case. Zip files are named for the eruption size modeled (e.g. "0.1km3", "1km3", "5km3" etc.). Other source parameters used for these simulations are described in the paper.
Each zip file contains similar contents. Below are the contents of the 0.1km3 directory, for illustration (note that a "d" in the left column indicates a directory).
d directory or filename Description
d 0.1km3 Output of 0.1km3 runs
0.1km3/0.1km3_simulations_Kidson_type.txt Percent Kidson types for each simulation
0.1km3/City_thicknesses.txt City thicknesses for each run
d 0.1km3/zip_files zip files of output from each run
0.1km3/zip_files/Run0001.zip zip file containing output for run #1
0.1km3/zip_files/Run0002.zip zip file containing output for run #2
0.1km3/zip_files/Run0003.zip zip file containing output for run #3
0.1km3/zip_files/Run0004.zip zip file containing output for run #4
. . .
CONTENTS OF THE FILES xxkm3_simulations_Kidson_type.txt
The input_summary.txt files contain a table with each row indicating the percent of each Kidson
type for each simulation. The first few lines of the file look like:
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Number Eruption start after duration+8 hrs percentage of each Kidson type
1 2 3 4 5 6 7 8 9 10 11 12
1 25-May-2002 16:52:06 26-May-2002 06:52:06 0 0 100 0 0 0 0 0 0 0 0 0
2 11-Aug-1982 03:51:53 11-Aug-1982 17:51:53 0 0 0 0 0 0 0 0 100 0 0 0
3 21-Apr-1989 14:59:53 22-Apr-1989 04:59:53 0 0 0 0 0 0 0 0 36 0 0 64
4 27-Mar-1999 13:21:51 28-Mar-1999 03:21:51 0 0 0 0 0 0 100 0 0 0 0 0
5 05-Jun-2014 17:56:13 06-Jun-2014 07:56:13 0 0 0 0 0 0 0 0 0 0 57 43
. . .
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Each row below the header gives:
1) The run number
2) The eruption start time
3) The end time of the eruption, plus 8 hours (the time over which we assume ash remains aiborne)
4) The percentage of each Kidson type over that period of time
CONTENTS OF THE City_thicknesses.txt FILES
Each City_thickness.txt file contains a table with thicknesses of ash (mm) at the main cities for
each run. The first few lines look like this:
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
City thicknesses for eruptions of 0.1km3
Run Auckland Hamilton Tauranga New Plymouth Napier Wellington
0001 0.000 0.000 0.000 0.000 0.122 0.000
0002 0.000 0.501 3.622 0.000 0.042 0.000
0003 0.000 0.000 0.001 0.000 6.440 0.000
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
CONTENTS OF EACH ZIP FILE
Each zip file contains the following:
Name Description
ash_arrivaltimes_airports.kmz kmz file showing ash arrival times at airports
ash_arrivaltimes_airports.txt Text file listing ash arrival times at airports
DepositArrivalTimes.txt Text file listing deposit arrival times at airports
DepositFile_ESRI_ASCII.txt ESRI-ASCII gridded text file of deposit thickness (mm)
Deposit.kmz kmz file of deposit thickness, can be opened in Google Earth
deposit_thickness_mm.gif gif map of deposit thickness (mm)
FORMAT OF DepositFile_ESRI_ASCII.txt
This gridded ascii file contains deposit thickness at each node in the model domain. The file
contains a header that looks like this:
NCOLS 120
NROWS 60
XLLCORNER 160.000
YLLCORNER -47.500
CELLSIZE 0.250
NODATA_VALUE 0.000
where NCOLS is the number of columns in the grid
NROWS is the number of rows in the grid
XLLCORNER is the longitude of the center of the lower-left (most southwest) node
YLLCORNER is the latitude of the center of the lower-left (most southwest) node
CELLSIZE is the spacing (degrees) between nodes
NODATA_VALUE is the value where there are no data
This header is followed by the gridded data, written in 10f10.3 format (10 numbers per row,
each number occupying 10 spaces with three digits to the right of the decimal). Each
row in the model could occupy several rows in the file due to the limitation of 10
numbers per row in the file. The first row is the southernmost row.
FORMAT OF DepositArrivalTimes.txt
This is a gridded ascii file of the arrival time of the deposit at each node in the model. The
deposit arrival time is given in hours after the eruption start. The file format is exactly the same
as that of DepositFile_ESRI_ASCII.txt. It should be noted that the NODATA_VALUE is incorrectly
given as -1.000. The NODATA_VALUE is actually -9999.0. This is the value given at each node if
ash never arrived at that node during the simulation.
FORMAT OF ash_arrivaltimes_airports.txt
This ascii file contains a table of ash arrival times at airports. An example of the first few lines of one file is:
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
ARRIVAL TIME OF ASH IN AREA MODELED BY ASH3D
simulation using input file: iwf25_Taupo_ESP.inp
Model run date: 2016.12.21, time UTC: 22:46
SOURCE PARAMETERS FOR SIMULATION OF: Taupo run |
Pulse start time Duration Plume height volume |
UTC hrs km feet km3 |
1 2002-05-25T16:52:00Z 24.00 20.0 65616. 5.00000 |
LOCATION | CLOUD |
| |
| |
(Airport code & ) Place name Latitude Longitude | Cloud Arrival Time Duration |
| hrs after |
| date/time UTC start hrs |
Pakatoa, N.Z., New Zealand -37.8069 174.8533 | 2002-05-26T01:47:00Z 8.92 15.95 |
Coromandel, New Zealand -36.7933 175.5167 | 2002-05-26T16:05:00Z 23.22 0.82 |
Whakatane, New Zealand -37.9222 176.9139 | 2002-05-25T16:53:00Z 0.03 26.70 |
Wanganui, New Zealand -39.9667 175.0242 | 2002-05-26T10:34:00Z 17.70 6.50 |
. . .
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
--Line 2 gives the name of the input file used (this was changed to ash3d_input.txt after the simulation);
--Line 3 gives the date and time of the simulations
--Lines 5-10 summarize the key eruption source parameters
--Lines 12 and onward give a table of arrival times, durations, and deposit thicknesses at all airports in the model domain that received ash. The columns in this table are the airport name, latitude, longitude, the time of arrival of the cloud in year-month-day-hour (UTC), the arrival time in hours after the eruption start, the number of hours the cloud remained overhead, the time when ash started falling at a given location (in year-month-day-hour UTC and in hours after the eruption start), the number of hours during which ash fell, the deposit thickness, and the US National Weather Service ranking of deposit thickness (e.g. “trace", “minor”, “substantial”, “heavy”).
(The right columns of the table had to be truncated in this explanation).
FORMAT OF KMZ files
Files with the .kmz suffix are in zipped keyhole markup language and can be opened in Google Earth(R)
Details on the contents of these files can be found on pages 19-22 of Mastin et al. (2013)
use of trade names does not imply endorsement of these products
Reference:
Mastin, L.G., Randall, M., J., Schwaiger, H. and Denlinger, R., 2013. User's Guide and Reference to Ash3d: A Three-Dimensional Model for Atmospheric Tephra Transport and Deposition, U.S. Geological Survey Open-File Report 2013-1122, pp. 48. http://pubs.er.usgs.gov/publication/ofr20131122
