The US Geological Survey routinely publishes ShakeMaps for significant earthquakes that occur across the globe. For more details, refer to the USGS website
These ShakeMap files are in HDF5 format, but RiskScape provides a special bookmark format option that makes these files easier to use in your models.
To use USGS ShakeMaps in RiskScape you will need the USGS plugin enabled.
A simple bookmark
To use a USGS ShakeMap in your model, you just need a simple bookmark like the following:
[bookmark example-shakemap] location = PATH/TO/shake_result.hdf format = usgs-shakemap description = Some details here about the specific quake are probably handy
This will load the ShakeMap as Coverage data, which makes it simple to sample. This means you can easily use the ShakeMap bookmark as a hazard-layer in your model.
RiskScape can download remote data via an HTTP link.
This means the
location in your bookmark could point directly at the ShakeMap download
link on the https://earthquake.usgs.gov/ website.
When the ShakeMap coverage is sampled (i.e. geospatially matched against an element-at-risk),
it will return the median PGA shaking value at that location in
In the ShakeMap file, the PGA values are actually store in
By default, RiskScape will automatically convert the values into
because that is usually easier to deal with in your Python function.
The ShakeMap data contains both the shaking mean and standard deviation for a given location. The RiskScape bookmark lets you apply some uncertainty to the shaking value you want to use.
For example, instead of using the median value you could use the ninety-fifth percentile.
To do this, simply specify the
percentile you want to use in the bookmark. For example:
[bookmark example-shakemap] location = PATH/TO/shake_result.hdf format = usgs-shakemap percentile = 95
By default RiskScape reads the PGA data for the
GREATER_OF_TWO_HORIZONTAL Intensity Measure Type
(using both the
However, you can read any dataset in the ShakeMap that you want.
This option is for advanced users who know what they are doing.
Specifying a ShakeMap
dataset will return that data as is.
RiskScape will not automatically convert from
g units when
dataset is set in the bookmark.
For example, to read the average MMI data, we simply specify the
dataset we want in the bookmark:
[bookmark example-shakemap] location = PATH/TO/shake_result.hdf format = usgs-shakemap dataset = /arrays/imts/GREATER_OF_TWO_HORIZONTAL/MMI/mean
Refer to the
units attribute for the HDF5 dataset as to what units the data values will be returned in.
In your bookmark, you can optionally Transform the sampled value to convert from one unit to another.
For example, to convert from
g units, you could add
map-value = exp(value) to your bookmark.
If you are not interested in the geospatial aspect of the ShakeMap data,
then you could alternatively read the dataset as relational data.
format = usgs-shakemap to
format = hdf5 will read the
dataset without including any geometry information.