1. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 Gabi Laske Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics La Jolla The Needs for/of Low-Frequency Seismology

2. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 * what is it good for? * what do we need? * what we usually see * some unexpected encounters * what is broad-band? * outlook Low-Frequency Seismology

3. What we look at

4. What is it good for?

6. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 * what is it good for? * what do we need? * what we usually see * some unexpected encounters * what is broad-band? * outlook Low-Frequency Seismology

7. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 Lots of good seismograms at lots of stations What Do We Need?

8. Instrument Responses at New South Pole Station QSPA

9. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 * observatory quality instruments * high signal-to-noise * several days of continuous data What do we need?

10. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 An Example at GEOSCOPE Station SSB in France

11. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 But How Much Data is Fit for Our Studies

12. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 Category “unload” Seismogram

13. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 Category “unload” Seismogram

14. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 Category “unload” Seismogram, if detected

15. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 Calibration Signals, A NIGHTMARE!

16. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 * what is it good for? * what do we need? * what we usually see * some unexpected encounters * what is broad-band? * outlook Low-Frequency Seismology

17. well, of course STS-1/KS54000... or so we think So, What Sensor Suits Us Best? but there is also

18. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 What Does This Imply for GSN etc? check all stations systematically!

19. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 Average Scoring for 20 Greatest EQ of last 10 Years

20. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 So what does this mean? not sure…. might be that KS54000 are at noisy sites

21. Noise Spectra at New South Pole Station QSPA Courtesy Jon Berger/ Kent Anderson 10mHz 1 mHz STS-1 appears to be quietest

22. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 * what is it good for? * what do we need? * what we usually see * some unexpected encounters * what is broad-band? * outlook Low-Frequency Seismology

23. The Three Greatest Earthquakes in 2003

24. VHZ V: 10s H: High Gain Z: vertical The Three Greatest Earthquakes in 2003

25. Other Stations? Primary Sensor: STS-1 KS54000/KS36000 Secondary Sensor: STS-2 CMG3B/CMG3T

27. pretty noisy site!

29. LHZ L: 1s H: High Gain Z: vertical

30. only 3.6h of data at IRIS-DMC! LHZ L: 1s H: High Gain Z: vertical

31. ! Quality of Spectra

32. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 Global Seismology Where Do We Go From Here?

33. The Current Global Coverage of Global Seismic Networks

34. ORION Workshop, Jan 04-08, 2004, San Juan, Puerto Rico ION-Integrated Observatory Network (??) OSN-Ocean Seismic Network (OSN-1 in 98) interdisciplinary!

35. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 * some sensors at GSN near end of lifetime * there are still huge holes in the GSN Motivation for this Audience

36. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 * what is it good for? * what do we need? * what we usually see * some unexpected encounters * what is broad-band? * outlook Low-Frequency Seismology

37. The Importance of Recording 100s Rayleigh Waves

41. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 * what is it good for? * what do we need? * what we usually see * some unexpected encounters * what is broad-band? * a link to shorter periods * outlook Low-Frequency Seismology

42. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 Data Logger Problems….A Thing of the Past?

43. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 Data Logger Problems….A Thing of the Past?

44. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 This Is Really Significant to Tomography!

45. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 * reliable broad-band sensor (down to 1mHz) (for observatory-quality stations) * low-power/high dynamic range sensor for ocean bottom * reliable data flow to DMC * for temporary deployments: cheap/attractive 120s sensors (no 40s sensor) * need to be able to orient horizontal components easily * timing needs to be accurate Outlook So, What Do We Need?

46. IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 Outlook So, What Do We Need? something that works like this … perhaps for VHZ!