Data Services Newsletter

Volume 17 : No 1 : Spring 2015

April 2015 M7.8 Nepal Earthquake

IRIS special events page

An informal collection of preliminary research results and comments from the research community. Learn more »

Newly available data at IRIS for the Nepal event

Since the Nepal event, the IRIS DMC acquired waveform data recorded during the mainshock (for various durations of time) from many new stations which were not initially available including:

  • IO.EVN: broadband station at the base of Mt. Everest operated by Ev-K2-CNR, OGS Italy
  • NQ.KATNP: a USGS NetQuakes station in Kathmandu
  • RM.SIM: a Regional Integrated Multi Hazard Early Warning System weather station
  • CB: China National Seismic Network (broadband)

Also, the USGS and the Quake Catcher Network (QCN) have 9 stations operating in the region, 5 of which were operational during the mainshock. Note: QCN data are currently not archived at IRIS.

Nepal_new_data2.png
Figure 1: Map of aftershocks (circles) since the April 25, 2015 M7.8 Nepal earthquake (yellow star), stations for which IRIS had data in real-time or near real-time (red triangles), stations with recently acquired data now available at IRIS (yellow triangles), and the Quake Catcher Network deployed by the USGS and colleagues following the event (blue triangles).

Mt_Everest_trace2.png
Figure 2: Broadband vertical trace from the closest broadband station for which IRIS has data available. The top trace shows the raw trace, which clipped, the bottom trace is a low-pass filtered version. Aftershocks are visible in both traces. Data contributed by the Ev-K2-CNR project, OGS Italy.

Download waveform data and Ground Motion Visualizations (GMVs) for the main shock and four largest aftershocks

Get recorded station waveform data using Wilber3. Find data products using the Searchable Product Depository

Date (UTC) Magnitude Links
2015-04-25 06:11:26 MWW 7.8 Wilber3 », GMV »
2015-04-25 06:45:20 MWW 6.6 Wilber3 », GMV »
2015-04-26 07:09:10 MWW 6.7 Wilber3 », GMV »
2015-05-12 07:05:19 MWW 7.3 Wilber3 », GMV »
2015-05-12 07:36:53 MWW 6.3 Wilber3 », GMV »

Table of Chinese broadband (CB network code) stations

Network Code Station code Latitude Longitude
CB CAD 31.0 97.5
CB CD2 30.91 103.7578
CB CN2 43.48 125.26
CB DL2 38.906 121.628
CB GOM 36.1984 94.8145
CB GTA 39.4 99.8167
CB GYA 26.46 106.664
CB GZH 23.6525 113.6525
CB HEH 50.253 127.41
CB HHC 40.85 111.564
CB KSH 39.517 75.923
CB LYN 34.55 112.47
CB LZH 36.087 103.8444
CB NAQ 32.25 92.25
CB NJ2 32.0517 118.8544
CB SNY 41.8278 123.578
CB TIA 36.21 117.124
CB TNC 25.029 98.52
CB WHN 30.5428 114.3539
CB XLT 43.9 116.079

Table of Quake Catcher Network (QCN) and NetQuake station name and type, sample rates, location, and installation and/or online date

Station Name Station Type Sample Rate (sps) Latitude Longitude Installed/Online Date
KATNP USGS NetQuake 200 27.7124 85.3156 Online before 25 April 2015
31523 QCN Onavi B 16-bit 50 27.6536 85.3028 Online before 25 April 2015
45298 QCN Onavi B 16-bit 50 27.6232 85.3223 Online before 25 April 2015
01339/31783 QCN Onavi B 16-bit 50 27.6905 85.2900 Online before 25 April 2015 (3rd floor of building)
49797 QCN Onavi B 16-bit 50 27.6844 85.3059 Installed 27 May 2015
49846 QCN Onavi B 16-bit 50 27.7215 85.3201 Installed 28 May 2015
49880 QCN Onavi B 16-bit 50 27.6785 85.3090 Installed 29 May 2015
49863 QCN Onavi B 16-bit 50 27.6493 85.3059 Installed 28 May 2015 (4th floor of building)
46326 QCN Android 50 27.6533 85.3027 Online before 25 April 2015 (no triggers)

Data Products access

Nepal_products.png
Figure 3: IRIS event-based Data Products experienced a dramatic spike in access following the Nepal event with over 12,000 unique hourly accesses in the week following the event.

More information

by Rob Newman , Alex Hutko and Manoch Bahavar (IRIS Data Management Center)