GFZ German research centre for geo sciences


The "German instrument pool for amphibian seismology" (Deutscher Geräte-Pool für amphibische Seismologie, DEPAS) provides broadband-onshore stations and ocean bottom seimometers for the preferred use within amphibious projects. The onshore component is maintained by the GFZ, the offshore component is operated by the Alfred-Wegener-Institute Helmholtz-Centre for Polar and Marine Research in Bremerhaven (AWI).

For the marine part of the DEPAS instrument pool look at

Recorder / EarthData PR6-24

The EDL, made by EARTH DATA (U.K.), is a digital recording system for stand-alone use.
Adaptor cables are available for all types of broadband seismometers belonging to the DEPAS pool.
Digitiser SetUp and Control can be done via serial link (manufacturer software). Additionally, a GFZ-GIPP made Recorder SetUp and Status View Software (including Digitiser Parameters) is available for the use of WIN/DOS and PocketPC based field palmtops. The GFZ User Software also supports Group SetUp; and the Control functions, as Status View and Configuration File Download, are performed as one-key commands. Data Retrieval is supported by GFZ User Software and by a set of Hard Disk Reading Adaptors. The adaptors convert IDE into SCSI for direct access to the hard disk from any LINUX PC.
A limited set of adaptors converts IDE for USB or FireWire connection. Have also an extended look at the recorder (154 kByte) and at the GFZ type casing (149 kByte). 

EarthData PR6-24 Recorder, 45 units
45 Units                                  3 Channels (all Units with USB connector)

Hard Disk, 150 units
25 Units                                     30.0 GByte
125 Units                                  40.0 GByte

Parameters - Input Signal
Channels                                    3 , plus 4 auxiliary used for seismometer mass position
Preamplification                     0.4; 1; 10
Clipping                                     Signal Channels: 40 Vpp@ PreAmp = 0.4 Auxiliary Channels: 20 Vpp

Digital Signal
Sampling Rate                         1; 2; 4; 5; 10; 20; 25; 40; 50; 75; 100, 120; 125; 150; 200; 250; 300; 375; 500; 600; 750; 1000 sps; 3000 sps (reduced dynamic range);
Resolution                                 MiniSEED, ASCII: 2.5 microVolt/digit ( @ PreAmp = 0.4 )
                                                       digitiser output: 3.9 nanoVolt/digit
Dynamic Range                       140 dB @ 100 sps 145 dB @ 25 sps (4 Byte digitiser output 150 dB)
                                                       96 dB @ 3000 sps (upper 2 Bytes only)

Time Keeping
Clock                                            1*10e-6 (TCXO)
Synchronisation                      GPS, continuously or cycled

Digitiser Buffer
RAM (volatile)                           16 MByte
Format                                         4 Byte

Data Storage
Hard Disk                                    30.0 GByte (Data Partition 27.3 GByte,FAT 32)
                                                        40.0 GByte (Data Partition 36.6 GByte, FAT 32)
Storage Format                         ASCII, upper 3 Bytes of digitiser output MiniSEED, compressed (Steim-1), based on upper 3 Bytes 'legacy', PR2400 multiplex (equivalent to digitiser output)

Physical Parameter
Power Consumption                 < 1.8 Watts (GPS cycled) to 2 Watts (GPS conti) @ 3*100 sps
Weight                                             Recorder, including disk: 4.3 kg (new series 3.75 kg
Operating Temperatures         Recorder and Disk: -20 to +65 °C

Connectors (Front Panel, Hard Disk)

Broadband Seismometer (3D) / GÜRALP CMG-40T

The GÜRALP CMG-3ESP Compact, made by GÜRALP, is a force balance broadband seismometer. Adaptor cables are available for EarthData recorders. 

Pool Contents
Seismometer, 45 units             GÜRALP CMG-3ESP Compact

Mechanical Parameters
Sensor                                            3 orthogonal sensors
Resonances                                  above 140 Hz
Control                                           Zero position (re-center pulse input)
                                                           Mass lock

Signal Output
Generator Constant                    2 * 1000 Vs/m
Response                                        Ground velocity from 60 sec to 50 Hz
Max. Output                                  ±20 V

Physical Parameters
Power Consumption                  0.75 Watts @ 12 V
Weight                                              8.3 kg
Operating Temperatures        -10 to +65 °C


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