How to participate
A) Magnetic Picks
When you publish a paper that depends on a set of magnetic picks, we
suggest you submit the data to us for distribution on our site. That
way others may get the most up-to-date data set in a common format.
We will help with getting the data into the correct format. For each
pick location you need to supply the following meta data:
|Chron:||The chron name [e.g., C13n]|
|AnomalyEnd:||End of anomaly being picked, i.e., young (y), old (o),
or center (c).|
|AnomEndQua:||Confidence in the anomaly end assignment. Ranges from
1 = anomaly end clearly listed in the original paper;
2 = some problem exist from original paper but there is
confidence in the anomaly end assignment
3 = anomaly end unclear in the original paper and the end
has been inferred by the data assembler.|
|CruiseName:||Cruise name designation (NGDC) if known, otherwise N/A.|
|Reference:||The publication reference [e.g., Cande++_1988_JGR]|
|GeeK2007:||The assigned age based on the Gee and Kent  time scale.
Note: Other time scales can be used via the Chron name.|
|IDMethod:||Typically "Magnetic Anomaly" but could be other identifiers
such as "Abyssal Hill".|
If you prefer to assemble this data using Arcinfo then you may consider this
GSFML template for magnetic pics.
We will build OGR/GMT data from your submission, from which we can build
KML files and shapefiles. See our Magnetic Lineations page for examples.
Submit your data via email to The GSFML Project.
B) Hellinger parameters and models
For published plate tectonic rotations we suggest you contribute your Hellinger input
files. In addition, if you wish you may also send us the Hellinger output files and
any document describing the data and solutions. See our Hellinger page for examples.
C) Seafloor Fabric
If you want to play the FZ game and contribute to the digitization
of the world's fracture zones and other lineations, here is how: Examine the JPG image of the
current FZ collection (below) and see if your area of interest needs to be digitized.
If features are already available, but you think you can do a better job,
then go ahead and digitize new lines. To make sure we all play the same game
there are a few rules you need to comply with:
Before you digitize, consider these points:
- You will use the free
Google Earth (GE) tool to digitize the features.
- You will use the latest VGG tiles from Sandwell and Smith, available
from Sandwell's website via this
VGG KMZ file. Open this file in GE.
- When you click the New Path button in GE,
a dialog box opens up.
If you know the name of the FZ, supply it as the name; otherwise leave
name as the default "untitled path". In the description field, please
give your name, institution, and email on a single line (e.g.,
P. Wessel, SOEST, firstname.lastname@example.org).
- Digitize by following the FZ trough (usually black in the images).
- If you do more than one FZ, organize the lines into a folder under Places.
- We currently maintain seven feature types as defined by Matthews et al., 2011 [link]:
Please make sure you identify the category of each digitized feature.
- FZ: Clear Fracture Zones
- FZLC: Less Clear Fracture Zones
- DZ: Discordant Zones
- PR: Propagating Ridges
- ER: Extinct Ridges
- VANOM: V-Anomalies
- UNCV: Unclassified V-Anomalies
To submit your data, right-click on the Folder entry in GE's Places and
send the KMZ file via email to The GSFML Project.
Please provide acknowledgment information (name, institution, funding if appropriate), and
any metadata relevant to your effort, and use "GSFML contribution" for the subject line (otherwise
it may not be processed).
- Your anchor points will be the beginning and end points of the FZ.
Take some time to determine the identifiable extent of the FZ.
- Do not over-digitize the FZ but supply "guide" points along the features
at a moderate interval, typically picking very clear points in the FZ
trough. The tracking software will determine the actual path of the
FZ by using these points, and it will not look beyond your anchor
points. It assumes the guide points are approximate and may not
necessarily lie exactly on the FZ track. The clearer the FZ trace
in the VGG image, the further apart your guide points may be.
- FZ sometimes split into strands; supply a guide point at any such forks.
- To draw lines where the FZ is poorly represented in the VGG (and you base
your digitization on other data or your intuition), use a denser
digitization interval and supply some information about what you
did (see below).
While we will keep all KMZ submissions in the database, we will use our judgment
in presenting only one version of each feature as "the best" on the website.
This version is what will be available to the general user.
Who can participate?
Scientists and graduate students in marine geophysics whose research makes use of
fracture zones. Those involved in plate tectonic reconstructions are the main
potential users of this site and best prepared to know what to digitize.
Why should I participate?
This project is similar to open source software projects in that the final
product (a global compilation of fracture zones lineaments) will
be available at no cost to anybody. However, those who participate and make a
contribution will get preferential treatment via access to our geospatial FZ data base
from which more specific queries will be possible. You will also be acknowledged
on the site as a contributor.
Additional Google Earth KML tiles
While we rely mostly on the VGG tiles for digitization, it is very convenient to be able to switch
between different representations (e.g., examining the free-air anomalies), look at the bathymetry,
the crustal ages, or the potential tilt [e.g., Miller and Sing, 1994]. Here are links to all the tiles:
- Matthews, K. J., Müller, R. D., Wessel, P. and Whittaker, J. M., 2011,
The tectonic fabric of the ocean basins, J. Geophys. Res., 116(B12109)
- Miller, H. G., and V. Sing (1994), Potential field tilt - a new concept for location
of potential field sources, J. Appl. Geophys., 32, 213-217.
- Wessel, P., Müller, R. D., Matthews, K. J., Whittaker, J. M., Myhill, R., and Chandler, M. T.,
The Global Seafloor Fabric and Magnetic Lineation Database Project, Geochem. Geophys. Geosyst., in prep.
- Wessel, P., Smith, W.H.F., Scharroo, R., and Luis, J., 2013, Generic Mapping Tools: Improved Version Released,
EOS Trans. AGU, 94, 409-410.
Maintained by Paul Wessel
Updated June 21, 2016.