DEPAS Pool

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 http://www.awi.de/en

The DEPAS is part of the Modular Earth Science Infrastructure | MESI at GFZ.

EarthData PR6-24 Recorder

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)
Power Consumption

GÜRALP CMG-3ESP Compact

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

Connectors

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