4. Software & Implementation Guide

Installing and operating a ShakeMap system is a non-trivial endeavor. While the software can be easily obtained, and installed and configured with a few hours work, there are a great many issues that need to be addressed when an organization considers deploying a ShakeMap system. In this section, we will discuss a number of these issues.

4.1. Implementation Considerations

4.1.1. Seismic Network

The single most important prerequisite for operating a ShakeMap system is the existence of a seismic network capable of determining the location and magnitude of significant earthquakes within minutes of their occurrence. This network must also produce parametric data for ShakeMap within minutes of the earthquake. The parametric data should come from free-field strong motion sensors with real-time or near–real-time telemetry, and minimally consist of the horizontal components of Peak Ground Acceleration (PGA) and Peak Ground Velocity (PGV), as well as (ideally) 5% damped pseudo- spectral acceleration (PSA) at 0.3, 1.0, and 3.0 sec periods.

In the absence of such a network, there is little reason to operate ShakeMap locally. The USGS operates a ShakeMap system that produces maps for significant global earthquakes within a few minutes of their occurrence, and incorporates any available data from the Global Seismic Network (GSN), “Did You Feel It?” (DYFI), and any other parametric data to which we have access. These maps are immediately delivered to the PAGER system and ShakeCast. It would be far simpler in many cases to obtain the ShakeMap products from the USGS (through the website or ShakeCast) and use them for local or regional response and recovery efforts, perhaps even hosting them on local servers, than to attempt to duplicate our existing system.

Even where a seismic network is operational, it may be preferable to work with the USGS to produce ShakeMaps. As the following sections will illustrate, running a ShakeMap system is a considerable operational undertaking, and in many instances it will strain the resources of local or regional networks. The USGS operates a fully-staffed, 24/7 operations center for global earthquakes and produces ShakeMaps on a daily basis. If a regional network’s parametric data can be made available to the USGS, the USGS’s global ShakeMap system will include that data in the processing, and finished ShakeMap products can be delivered via ShakeCast for local consumption. Please contact us if you are interested in this kind of arrangement.

4.1.2. Seismic Stations and Parametric Data

As mentioned above, seismic waveform or parametric data must be communicated to the processing center in real-time or near—real–time. The sensors must be “free field” (i.e., not located in, or adjacent to, large structures) and installed in accordance with modern standard practices. Strong-motion instruments are preferred for ShakeMap, as broadband instruments typically clip when ground motions reach the level of interest to ShakeMap. Co-located strong-motion and broadband instruments can, however, increase the dynamic range of a station and its overall usefulness, but the network operator is responsible for specifying the crossover from broadband to strong motion, and ShakeMap should be presented only with the amplitudes from the favored instrument. Off-scale, clipped, below-noise, or otherwise unreliable data must be flagged or omitted from the ShakeMap input files. Horizontal components are mandatory—ShakeMap does not use vertical components.

At a minimum, the network must produce PGA and PGV for the ShakeMap stations, but PSA (at 0.3, 1.0, and 3.0 sec) is also desirable. The algorithms used to compute the parametric data should be verified against known standards. ShakeMap can be quite helpful in highlighting grossly mis-calibrated stations, but it is best to find these (and more subtle) errors before a large earthquake strikes.

Intensity data from the USGS’s DYFI system (or an equivalent regional internet intensity system) is acceptable as input to ShakeMap; however, care should be exercised with international DYFI data, as it is often aggregated by city and therefore may be too coarse-grained for large-scale maps.

4.1.3. Triggering ShakeMap

The operator must give careful consideration to the way ShakeMap will be triggered. Unless an operator is constantly standing by to run ShakeMap, the system must be automatic to be useful. The operator must select the boundaries of the region ShakeMap will cover and the minimum earthquake magnitude that will trigger a run. These choices will be influenced by the reliability of the network’s earthquake location and magnitude data over the region in question. The operator must also consider that a large earthquake may occur outside their region of responsibility, but have effects inside their region.

The ShakeMap software is distributed with a program for responding to event triggers and queuing events to be processed, but it is only applicable to the AQMS network software. While this software can serve as a guide, users of other systems (e.g., Antelope, Earthworm) will need to develop their own triggering systems.

Once triggered, ShakeMap will expect to find event and parametric data files in the event’s input directory. Whether the amplitudes are retrieved from a database or stored in files, it is the operator’s responsibility to provide ShakeMap with properly formatted files. Again, example programs are distributed with ShakeMap, but operators should anticipate that some coding may be necessary.

4.1.4. System Configuration

While it is relatively easy to install and run the ShakeMap software, a great deal of consideration is needed to properly configure the system for a particular region. ShakeMap presents the operator with a large number of configuration options, and these options will directly affect the accuracy and reliability of the products. The operator must select the proper GMPE or GMPEs for the region, and specify under which conditions they will be used. An appropriate Ground-Motion–Intensity Conversion Equation (GMICE) must likewise be chosen. The operator may also elect to use an Intensity Prediction Equation (IPE) or to use the default virtual IPE. For best results, the operator will need to provide a Vs30 grid, and while the USGS’s Vs30 server can supply such a grid based on topographic slope, a grid based on regional geology is preferable [1]. The user must also decide whether to use GMPE-native or Borcherdt-style site correction factors. This is just a partial list of configuration choices. There are numerous other configurable parameters, all of which must be carefully chosen.

While the default ShakeMap webpages are configurable, they are fairly rudimentary and outdated. In addition, the webpages and ShakeMap products are all in English. Operators wishing more sophisticated webpages or non-English support can anticipate a substantial investment in bringing the system online. Some modifications of the ShakeMap software may be required for languages other than English, but such modifications may make it more difficult to update the software.

For further information on ShakeMap configuration, see the Software Guide and the ShakeMap configuration files themselves.

4.1.5. Operations

Once an organization begins producing and distributing ShakeMaps, end users will begin to depend upon them and develop systems that incorporate ShakeMap products into their response and recovery operations. This means that it essentially becomes mandatory to produce ShakeMaps following significant earthquakes, and failure to do so is extremely conspicuous. A robust ShakeMap operation requires the 24/7 availability of operational personnel. If the facility is not continuously manned, on-call staff must be designated, and those staff must have the ability to access and operate the ShakeMap system remotely. Significant earthquakes almost always require some manual intervention (changing map scale, re-centering, addition of finite fault, inclusion/exclusion of data, etc.), and experienced personnel are required to evaluate the situation and perform the necessary tasks.

There are additional, more routine, operational considerations. An experienced seismologist should routinely review all of the ShakeMaps produced by the system and take action to correct any deficiencies. A network seismologist should also review the inputs and outputs of ShakeMap to insure that all stations are producing appropriate data. A ShakeMap operator should routinely review all ShakeMap processes, logs, databases, and outputs to insure the system is operating as expected.

The ShakeMap software is usually updated a few times a year. These updates contain important bug fixes, new functionality, new products, and general improvements. An operator must review the change logs, decide when to apply the updates, and test the updated software before it is put into production mode. Occasionally it may be desirable to rerun earlier events or scenarios to take advantage of the capabilities of the new code.

Hardware and software systems will need to be monitored and maintained for around-the- clock availability. This includes not just the seismic network and ShakeMap systems, but also web servers and other network hardware and software required for delivering products to end users. The personnel responsible for these systems must be on-call and able to access the necessary systems remotely. Automatic monitoring of mission-critical hardware and software is strongly encouraged. These systems should also have several hours of backup power in case of an outage. Periodic outage tests should be conducted to ensure that all necessary systems remain operational.

As mentioned above, users can be expected to make use of ShakeMaps in a variety of ways. However, many organizations that could make use of ShakeMap products are unaware of ShakeMap and the ways it could serve their earthquake response and recovery needs. We have found that a sustained outreach effort is necessary to maximize the adoption of ShakeMap and, thus, its value to society. Potential end users include public utilities, government and private transportation companies, police and fire departments, regional and national emergency response organizations, private companies with distributed facilities (e.g., banks, chain stores, telecoms), insurance companies, investment houses, and many others. Not only can ShakeMap-improved response efforts benefit post-earthquake recovery, these organizations can provide much-needed support for network and ShakeMap operations. It is highly recommended that regional networks considering the implementation of ShakeMap develop a detailed outreach plan.

4.1.6. Scenarios

One important use of ShakeMap is the generation of earthquake scenarios. Scenarios are predictive maps of the potential shaking resulting from hypothetical future (or past) earthquakes. Scenarios can be used for planning exercises, public information, or research. Some users may request specific scenarios, but it is generally worthwhile to develop a suite of scenarios to cover the likely earthquake hazards of a region. At the USGS, we have begun using disaggregated hazard maps as the basis for our nationwide scenario project. In other words, we separate out the individual earthquakes (and causative faults) that together comprise the hazard in a probabilistic hazard map. The disaggregated maps represent the best scientific consensus of the probable earthquakes in a region, and should be sufficient for most uses. Requests for custom scenarios should be carefully evaluated. The earthquakes represented should be credible in terms of both the causative fault and the magnitude. In most cases, one of the disaggregated hazard scenarios should suffice.

4.1.7. Backup

Because of the importance of ShakeMap, it is advisable to run redundant systems. Most ShakeMap operations have a primary and backup machine. The backup machine runs events as if it were the primary, except it does not transfer its products to the web or other destinations. If the primary server fails, the backup can be switched over to primary merely by changing the transfer configuration. This arrangement is also useful when software updates are available. The update can be applied and tested on the backup system. Once it is deemed to be operating correctly, it can be made primary, and the primary server can be updated.

Since most seismic networks are operated from earthquake-prone regions, there is also the potential that the entire facility will be taken offline. For this reason, it is desirable to have a backup system operating in a remote location, preferably many kilometers away.

As we have mentioned elsewhere, the USGS makes ShakeMaps for global earthquakes and provides backup to U.S. regional networks. If you would like to discuss remote backup for your ShakeMap system, please contact us.

4.2. ShakeMap Implementation Checklist

The checklist below is based on the one we use when discussing ShakeMap operations with active or potential producers within the USGS’s Advanced National Seismic System (ANSS). While some of the issues are ANSS-specific, there may be analogous considerations for other regional or national networks.

  1. Triggering
    1. Automatic Triggering System. How is ShakeMap triggered and how does it access or receive parametric data? How is robustness of this approach achieved?
    2. Location & Magnitude Reliability. Are there limitations to location and magnitude determination by the regional network that would adversely affect automatic ShakeMap products?
    3. Regional Coverage. What are the boundaries of the area within which the local network will generate ShakeMaps?
    4. Alarm Region. For events outside ShakeMap boundaries, is a ShakeMap run initiated? Under what conditions?
    5. ShakeMap ID. Does the naming of ShakeMap ID follow the ANSS convention? If not, can they be easily associated with the authoritative ID?
  2. Station Coverage and Parametric Data
    1. Real-time or near–real-time data flow. What are the types and distribution of stations contributing to ShakeMap? Are all stations “ShakeMap-quality”?
    2. Parametric Data. How are the parametric data computed? (Five parameters: PGA, PGV, and three periods of PSA.)
    3. Are parametric data imported from other sources (NSMP-triggered stations, state or commercial agencies, neighboring networks, etc.)? How are these integrated with the ShakeMap input?
    4. Are “Did You Feel It?” data used as input?
    5. Co-location of different sensor types, priorities, and preventing redundant input data. How are co-located instruments resolved by the network to produce only a single (best) set of amplitudes for ShakeMap?
  3. System Specifications
    1. Grind parameters. Review the parameters in grind.conf. How were they determined?
      1. GMPEs. Which Ground-Motion Prediction Equations are used, and under what conditions?
      2. IPEs. Which Intensity Prediction Equations are used, and under what circumstances?
      3. GMICEs. Which Ground-Motion–Intensity Conversion Equations are used?
      4. Site Amplification. How are site conditions established and what amplifications are used (GMPE-native, Borcherdt-style)?
      5. Other parameters. Grid spacing, map area, outlier levels, bias parameters. Have all parameters been evaluated for optimal performance?
      6. Shake.conf. When is map size increased, PSA and HAZUS output produced, etc.?
    2. Spatial Correlation Function. Which spatial correlation function is used?
    3. Basin response. Is a basin response applied in any areas? If so, how was the basin depth file produced, and are predicted ground motions consistent with reality?
  4. Operations
    1. Which version of ShakeMap is operational? Who is responsible for updating the software when updates are released? When and how are the updates performed?
    2. Who is responsible for routine scientific review of ShakeMaps produced by the network? Do these people receive alarms when ShakeMaps are produced?
    3. Who is responsible for routine operational review of the ShakeMap system (checking logs, process and database monitoring, etc.)? When are reviews performed?
    4. Reprocessing. Under what circumstances are events reprocessed (new data, change in source parameters, etc.)? What about in the longer term (ShakeMap software updates, changes in operational parameters)?
    5. Finite faults. For larger earthquakes, who is responsible for producing a finite fault model for inclusion in ShakeMap? What procedures are in place for assuring this is done?
    6. Aftershock exclusion. How will you change the triggering threshold immediately after a major earthquake in your region?
    7. Version history. Under what circumstances are maps (and their input data) preserved using ShakeMap versioning?
    8. Have there been any local changes to the ShakeMap software that will hinder upgrades? Can these customizations be incorporated into the ShakeMap distribution for easier upgrades? If not, how can they be structured to accommodate easy upgrades of ShakeMap?
    9. What is the hardware for ShakeMap processing and for local web service?
    10. How is hardware redundancy achieved?
    11. Are the hardware and software systems automatically monitored? Do they generate alerts when problems are detected?
  5. Product Distribution and Uniformity
    1. Are products delivered to Earthquake Program Web Servers via PDL?
    2. Are local webpages produced? Where do they reside? How is ShakeMap transferred? Are redundant web servers and 24/7 support available?
    3. Are regional ShakeMap webpages customized to reflect regional configurations and implementation specifics?
  6. ANSS Coordination
    1. Provide Software/Feedback to ANSS. To benefit current operators and to ensure compatibility and ease of installing new ShakeMap software releases, changes to ShakeMap software (above and beyond configuration changes) should be provided to Bruce Worden for review, standardization, and inclusion in new releases.
    2. Provide contacts, their background, and roles in implementation, coordination, and operations.
    3. Are all responsible parties subscribed to the shake-dev mailing list?
  7. User Coordination: List significant users and outline any outreach efforts or plans. It is very useful to have a feeling for which users will rely on ShakeMap in each region, as well as to coordinate efforts for users of ShakeMaps for multiple regions (e.g., FEMA, DHS, Military).
  8. Scenarios and Archives
    1. Scenario earthquakes should be made to be consistent with USGS National Hazard Maps, both with attenuation relations and in source parameterization. Coordination with the National Earthquake Information Center (NEIC) is essential.
    2. Is a copy of scenarios also available on the USGS web site?
    3. How and when will scenarios be reprocessed?
    4. Archive “final” ShakeMaps for significant events. Many users want ShakeMaps for significant events “frozen in time”. Once a ShakeMap gets used as a reference for damage-loss modelers, insurance investigators, and researchers, there needs to be an archival version of these events. Once all the available ground-motion data have been collected and included in ShakeMap, that Version of the map needs to be kept available even if additional updates are made. (This process has not yet been fully vetted.)
  9. Backup Strategy
    1. If the primary system fails, what provisions exist for a backup system or another network to take over ShakeMap operations? Is this backup automatic or manual?
    2. If the entire facility goes offline, is there an off-site backup?
    3. Are waveform or parametric data transmitted to NEIC for national-level backup?
  10. Feedback: Do you have any recommendations for further support, software, features, etc.?

4.3. Software Availability & Software Guide

ShakeMap requires the freely available PERL, MySQL, and GMT (Generic Mapping Tools), as well as a few other packages. PERL and GMT are used quite extensively, so any background with them is advantageous. You will need to assemble the basic GMT-formatted basemaps, road, city data files, etc., but such data may already be available for your area.

The ShakeMap software is freely available, open-source, and distributed under a Public Domain License. It runs on Solaris, FreeBSD, Mac OS X, (U)nix, and numerous versions of Linux (including Red Hat and Debian). It does not run on Windows. See the Software Guide for more information. The software is available as a SubVersion checkout from:

https://vault.gps.caltech.edu/repos/products/shakemap/tags/release-3.5/

Note

Do not attempt to install ShakeMap on Ubuntu Linux. It has been nothing but a problem for everyone who has tried it, and we will no longer provide support for this operating system.

The Software Guide included in the doc directory of the distribution will always be the most up-to-date and should be consulted when installing and configuring ShakeMap. The Software Guide may also be obtained by download. This version of Guide is not guaranteed to be the most up-to-date, however. It should be used only to familiarize oneself with the general requirements of installing and operating ShakeMap. When installing the software, the Guide in the doc directory of the software distribution should be followed.

We strongly recommend that ShakeMap operators and users sign up for the shake-dev mailing list:

https://geohazards.usgs.gov/mailman/listinfo/shake-dev

We use this mailing list to communicate software updates, as well as provide support when users have problems, suggestions, etc.

[1]

The VS30 server currently provides GMT grd files in pixel node registration and ShakeMap works in gridline node registration. You can fix your Vs30 file by:

grdsample your_vs30_grid.grd -Gnew_file_name.grd –T

You then configure grind.conf to look at new_file_name.grd. See grind.conf for details.