The University of Alaska Fairbanks, Geophysical Institute

Seismological Computing Facility

(As it existed in 1995. It's grown significantly since then.)

Major Projects Served
- The Alaska Earthquake Information Center (AEIC).
- The Alaska Volcano Observatory (AVO).
- The Geophysical Institute's Seismology and Volcanology research and graduate education groups.
Local Area Network
- Presently a single Cabletron MMAC-8 network concentrator, with three bridged Ethernet segments, connects the Facility's more than 40 systems via 10-Base-T (twisted pair copper wiring). An additional segment serves AVO via an external bridge and an isolated PC data acquisition network.
- The Facility has a dedicated Class C Internet subnetwork (137.229.32.xxx, equivalent to the domain giseis.alaska.edu).
- This subnetwork is presently bridged to the Institute's backbone and connected via 10-Base-F (Ethernet over fiber-optics) to a Cisco router. There is a continuing effort to upgrade this to an ATM connection to provide high bandwidth communication between the Facility and the Cray-based Arctic Region Super Computing Center and Silicon Graphics-based scientific visualization centers.
Data Acquisition Systems
- Two Masscomp (Concurrent) 5600 Real-Time UNIX systems, one primary and one backup, each digitizing analog signals from approximately 150 seismograph stations at 120 Hz with a resolution of 12 bits. Continuous data is acquired at a rate of nearly 3 gigabytes per day out of which an average of about 13 events are automatically detected and analyzed. This yields a current data rate of roughly one terabyte of data and 5,000 events recorded per year.
- The JADE software package, comprised of approximately 31,000 lines of "C" code developed by the Facility, is used to digitize, continuously record, detect events, and automatically process network data. The main program in this package is "Just Another Detector of Events" (JADE).
- Four 386 & 486 MS-DOS PCs collect and automatically analyze data from seismograph networks on selected volcanoes. A software package centered around a program called Xdetect and developed primarily by the U. S. Geological Survey is used to do the automatic acquisition and processing required for prediction, monitoring, and analysis of volcanic eruptions.
- Additional, enhanced, Ethernet-oriented versions of these PC acquisition systems are being integrated with UNIX servers and workstations to replace the aging Masscomps. This is another joint development effort with the U. S. Geological Survey.
- Two T1 communication links from GTE Lenkurt are utilized to bring most of the Alaskan Seismograph Network data into this Facility.
- A Best, Inc. 12 KVA Uninterruptible Power Supply (UPS) and 50 KVA generator are used to provide reliable power to all of the electronics and computer equipment associated with fundamental data acquisition.
Data Analysis Systems
- Sixteen Sun SPARCstation 20, 5, 4/370, IPX, ELC, and 1+ workstations provide computing power to users in a Solaris 2.4 (Unix) and Motif/X-Windows environment.
- Workstation access is also provided by thirteen X-Windows servers (graphics terminals) from Network Computing Devices (NCD) including 16 and 19 inch monochrome and 17 and 21 inch color RISC-based systems.
- Additional workstations are always in demand as both the operational and research work supported by this Facility are still rapidly expanding.
- Xpick, a copyrighted, trademarked, and portable "C" program of approximately 32,000 lines developed by this Facility, enables efficient interactive graphical analysis of recorded earthquake data in an X-windows environment. This program has been licensed to approximately 30 seismological institutions internationally.
- Many commercial software packages are used. Most notably MATLAB from The Math Works, Inc. and the NCAR graphics library for visualization; and FrameMaker from Frame Technologies and Microsoft Word for document publishing. A multitude of scientific applications and utility packages developed locally and imported from many other institutions also provide vital capabilities.
- Approximately 20 assorted 386, 486, and Pentium PCs and a few Macintoshs are also utilized.
- Printing is accomplished using three PostScript printers and several HP Laserjets.
Data Management & Access
- Presently a Sun SS20 is providing primary Network File System (NFS) and Network Information System (NIS+) services.
- More than 30 GB of magnetic disk storage is connected via SCSI and SCSI-2 to various Suns and available via NFS. NIS+ is utilized to make all disk partitions accessible in an identical and transparent manner from all workstations in the Facility.
- A data management and access system is being developed utilizing the Earthworm automatic processing software, in collaboration with the Earthworm team at the U. S. Geological Survey; and utilizing the Datascope package developed by the IRIS Joint Seismic Program Center located in Boulder, Colorado.
Archived Data Volume
- Approximately five terabytes of digital data collected from the state-wide seismograph network is archived on several hundred 8mm Exabyte and 4mm DAT tapes providing a nearly continuous 120 Hertz record since 1988.
- Several Exabyte 8505 and HP and Archive DAT drives are used to create and allow access to these tapes.
- Eight Symmetrical Technologies erasable magneto-optical disk drives are used to provide NFS access to more than 100 accumulated 640 megabyte removable disks.
- Measurements such as phase arrival times and amplitudes are stored on-line from more than 66,000 Alaskan earthquakes since the seismograph network was established in 1967.