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Media Release

New ultra-low latency data transmission protocol for Earthquake Early Warning (EEW) unveiled at AGU Fall Meeting, San Francisco. GDI can transmit data 25 times faster than standard EEW protocols.

Güralp Systems Ltd, the leading global provider of seismic monitoring instrumentation and solutions, unveiled a new, free-licence, data transmission protocol that dramatically reduces the time it takes seismic instrumentation to inform Earthquake Early Warning (EEW) systems that an earthquake has occurred.

Güralp has devised a packetized data transmission protocol called Güralp Data Interchange, (GDI) that allows seismic waveforms to be transmitted sample by sample, as they are acquired by the instrumentation. To further improve speed, GDI adapts the size of the data packets it sends to suit the bandwidth available in the network. This means that transmission time is absolutely minimised for the EEW network and data can be received in as little as 30 ms.

Data protocols currently used are also packetized systems, however they require the packet to be filled to a specific size before the packet can be transmitted – and it’s this that introduces delays into the transmission process. Delays can extend to one second or more.

Working in collaboration with gempa, GDI has been incorporated into a plug-in for gempa’s SeisComPro software and is now available to existing SeisComPro customers via the CAPS plugin. For EEW networks not using SeisComPro, GDI is available as a free-license, source code download for integration into existing networks.

Dr. Chris Potts, Güralp Executive Chairman sets out the reasoning for making GDI free to use:

“As soon as we realised GDI’s potential we made the decision to make it a free-licence product. After all, we are foremost, an instrument manufacturer and not a software developer. By providing access to all interested parties, we can ensure that the global community will benefit from GDI and we hope that, by doing this, the EEW community will also contribute to its evolution, for everyone’s benefit.”

On incorporating GDI into SeisComPro, Bernd Weber, CEO, gempa GmbH explains

“GDI is one of the few acquisition modules fulfilling the requirements of EEW. With the integration into SeisComPro a modern sophisticated turnkey solution can be provided to the EEW community.”

The greatest benefit of GDI is when it is combined with low latency digitisation, such as the causal filtering in the Güralp Minimus digitiser (see Minimus brochure for more information). In this example, both digitisation and transmission can be achieved in ~40 ms, significantly less than the typical data delivery time of 1 s using other protocols.

For more information on GDI and how to download the source-code, view the GDI datasheet.

About EEW systems:

EEW systems notify users in a local or regional network when an earthquake event occurs, usually with an indication of the expected severity of the earthquake and an approximate arrival time. Generally the alert will be issued in the manner of a few, to tens, of seconds before the earthquake reaches the users. Although short, this warning time allows for automated systems to shut down services such as elevators, gas supplies and even transport networks. In addition it allows time for people to take steps to protect themselves under tables or in doorways.

The EEW community seek to maximise the warning time so that more sophisticated safety measures can be implemented. For instrument manufacturers, there are two stages where instrument design can contribute to reducing these delays - firstly the processing time required to analyse the seismic data as it arrives (this is necessary to assess the earthquake severity and location) and secondly, the time it takes for the seismic data to be transmitted to the alert system (this is often constrained by the telecommunications network being used).



For urgent enquiries please call 020 3727 1000 and speak to Fergus Wheeler, Louisa Feltes or Jess Gill. 






Güralp Systems Ltd.( is a leading global provider of sophisticated seismic monitoring solutions used to understand natural seismological events such as earthquakes, aftershocks and volcanos, as well as induced seismic events, or seismic signals, resulting from human activity.

Our solutions are used in research, civil and industrial applications to increase understanding, optimise processes and to protect people and the environment. Our equipment is installed in all major ocean basins and across all continents worldwide.

Our instruments range in performance from very low frequency, very low noise for global seismology to high dynamic range instruments for local, strong motion monitoring. Our sensors and can be supplied for deployment at the surface, in boreholes and on the ocean bottom. We also provide data acquisition equipment, power and communication accessories and data interpretation software.

Our services include installation and commissioning; network operation; repair and maintenance services; data processing and interpretation.

Headquartered in Reading, in the UK, we have been operating for more than 30 years and have established a global network of distributors who provide local customer support and sales services.

gempa GmbH ( offers a wide range of services and products to monitor, process and analyze elemental activity.

We focus on products around the real-time processing system SeisComP3 which has been developed within the GITEWS (German Indonesian Tsunami Early Warning System) project by GFZ German Research Centre for Geosciences initially. We continue the development and maintenance of SeisComP3.

Primarily developed for seismology (earthquake monitoring) we extended the framework SeisComP3 to monitor, process and analyze data from for instance buoys and tide gauges for Tsunami Early Warning Systems.

At the center of our attention stand workable and easy to use solutions for your individual challenges.

We are collaborating with international institutions and companies, we work with interesting people all over the world. In a nutshell: we love what we are doing!



Affinity front

Media Release

Güralp, the leading global provider of force feedback seismic monitoring instrumentation is launching a new low power, high fidelity, integrated digitiser and communications unit called Affinity; and Fortis, a strong motion accelerometer that has been designed to deliver ‘best in class’ performance.



The Affinity’s key features include full 24-bit resolution; an exceptionally low noise floor of >138 dB at 100sps; and sampling rates of up to 4000 samples per second.

For the first time with Affinity, Güralp will allow users access to the software environment to customise data reading, writing and signal processing. By opening the source of internal data handling and processing software, users will be able to expand the versatility of the Affinity for applications such as earthquake early warning; data triggers over low bandwidth; and applications’ proprietary data transfer protocols.

Philip Hill, Engineering Director at Güralp explains:

“When we made the decision to open up aspects of the Affinity software we did so largely in response to customer demand. The Affinity is a high performance piece of kit well suited to complex network arrangements and is built on open source Linux. Extending this open concept to include our data handling and control interface software allows users to incorporate functionality traditionally only possible with external hardware and software.  The open source concept seems to be the ultimate way in which to respond to our customer's requirements.”

The Affinity also features a fast, fully interactive user interface with state of the art timing protocols and a switchable gain to enable a wide variety of different instruments, from the simplest of geophones, to infrasound sensors and, of course, seismometers.



The Fortis is a low-power (1.3 Watt), slim-line design, just 125 mm in diameter and 99 mm high with its optional feet. The Fortis incorporates state of the art switched gain levels that will allow the instrument to perform optimally in a wide range of earthquake, structural health and civil engineering applications.

The unparalleled low noise of the instrument finally allows the gap between traditional strong motion instrumentation and the weak motion seismometer to be bridged. The instrument naturally benefits from both flat frequency response as well as controlled and flat phase response over the passband. This is a pre-requisite for accurate picking and stacking algorithms to function optimally.

For further details of both of these new products, AGU registrants can visit Güralp at stand 344.

If you are not attending AGU, you can view the product brochures online: Affinity brochure; Fortis Brochure.









Guralp Systems Limited
Midas House
Calleva Park

Tel: +44 118 981 9056
Fax: +44 118 981 9943