When time allows, I'll post channel sets that I create to look at earthquakes on this "blog".

Instructions: To copy one of the channel sets on the iPad, press and hold your finger on part of the channel list. When you release you finger you will see text-selection handles. Select the channel set and choose copy. Then navigate to the seismogram settings tab and press and hold on the current channel list. When you release you will see text-selection options; choose Select All and then choose Paste to replace the current with a new set.

Sunday
Feb262012

26 February SW Siberia Earthquake

The 26 February, 2012 magnitude 6.7 southwestern Siberia earthquake is very close to a similar magnitude event that occurred on 2011 December 27 15:21:56 UTC. The December earthquake was predominantly strike-slip

Station ULN, is a few hundred kilometers from the Siberian quake. Here is a channel set with short-period filters that should enhance the smaller aftershocks.

IU; ULN; 00; BHZ; Ulaanbaatar, Mongolia (Up-Down); 0.2; 5;
IU; ULN; 00; BHE; Ulaanbaatar, Mongolia (East-West); 0.2; 5;
IU; ULN; 00; BHN; Ulaanbaatar, Mongolia (North-South); 0.2; 5;

Here are the same stations with the filters off

IU; ULN; 00; BHZ; Ulaanbaatar, Mongolia (Up-Down)
IU; ULN; 00; BHE; Ulaanbaatar, Mongolia (East-West)
IU; ULN; 00; BHE; Ulaanbaatar, Mongolia (North-South)

You can download both with the filter and with a longer-period filter to see the signals in two different bandwidths.

 

Thursday
Feb162012

16 February, 2012 Northern SF Bay

Listed below is a SF Bay area channel set with one more station (Lucas Valley) than listed in the default set from the popover menu in the iPad app. The additional station is in a borehole just north of the San Rafael. The station is part of the Plate Boundary Observatory Network, which is part of the National-Science-Foundation supported EarthScope Initiative (http://earthscope.org). The seismogram sample rate on that station is high (100 samples per second), which requires more bandwidth to transmit than the other stations. If you keep your requests small, this shouldn't be an issue. But I left it off the default list for that reason.

To see the seismograms from the  along the Hayward fault system near Berkeley, CA, use the "Near" filter settings and request about 3 minutes duration of data.

BK; SAO; 00; BHZ; SAO, HOLLISTER, CA, USA (VERTICAL);
BK; SAO; 00; BHE; SAO, HOLLISTER, CA, USA (EAST);
BK; SAO; 00; BHN; SAO, HOLLISTER, CA, USA (NORTH);
PB; B057; --; EHZ; LUCAS VALLEY, CA (VERTICAL);
PB; B057; --; EH1; LUCAS VALLEY, CA (NORTH);
PB; B057; --; EH2; LUCAS VALLEY, CA (EAST);
BK; MCCM; 00; BHZ; MCCM, MARSHALL, CA, USA (VERTICAL);
BK; MCCM; 00; BHE; MCCM, MARSHALL, CA, USA (EAST);
BK; MCCM; 00; BHN; MCCM, MARSHALL, CA, USA (NORTH);
Map from the US Geological Survey.
Monday
Feb132012

13 February, 2012 Northern California

A magnitude about 5 earthquake occurred in northern California this afternoon. Aftershocks should be visible on the station listed below. The station is operated by the EarthScope Project and is about 50-75 km from the earthquake, so only the larger aftershocks will be visible at the site.

TA; M02C; --; BHZ; Callahan, CA, USA (Up-Down); 2.0;4.0 
TA; M02C; --; BHE; Callahan, CA, USA (East-West); 2.0;4.0
TA; M02C; --; BHN; Callahan, CA, USA (North-South); 2.0;4.0

If you want to try to monitor the activity, you could stream (use the automatic updates every five minutes or so) about 15 minutes of data, enter a "*" in the Sample Rate field.

 

Thursday
Jan262012

A Seismic Station In Northern Italy

A magnitude about 5 earthquake occurred in northern Italy, near the city of Reggio Emilia yesterday. Aftershocks should be visible on the station listed below. The earthquake was felt in Milan. The station is operated by the MEDNET Project, Rome, Italy and is about 50-75 km from the earthquake, so only the larger aftershocks will be visible at the site.

MN; VLC; --; BHZ; Villacollemandina, Italy (Up-Down) 
MN; VLC; --; BHE; Villacollemandina, Italy (East-West) 
MN; VLC; --; BHN; Villacollemandina, Italy (North-South)

If you want to try to monitor the activity, you could stream (use the automatic updates every five minutes or so) about 15 minutes of data, enter a "*" in the Sample Rate field,  and use the "Near" filters.

Saturday
Dec312011

A Station Near the Youngstown, Ohio, 31 December, 2011 M 4.0 Earthquake

The largest earthquake in a series that have been occurring beneath the Youngstown, Ohio region during the last year. The earthquakes are interesting because they are in the general vicinity of an injection well. Whether these earthquakes are related to the fluid injections remains unknown. This is the only injection well in the state out of over 150 that has had nearby seismicity.

Here's a channel set for a nearby station, in Pennsylvania.

TA; N54A; --; BHZ; Portersville, PA, USA (Up-Down) 
TA; N54A; --; BHE; Portersville, PA, USA (East-West) 
TA; N54A; --; BHN; Portersville, PA, USA (North-South)

Here are the ground displacement seismograms.

Friday
Dec232011

Detecting Aftershocks of the 23 December, 2011 Off-the-coast of Christchurch, New Zealand Earthquakes

There are no seismic stations very close to Christchurch available in real time (there are many seismometers deployed in the region). The closest station in the general area of the South Island city is to the west and south at Ratta Peaks. 

NZ; RPZ; 10; HHZ; Rata Peaks, NZ (Up-Down); 1; 4
NZ; RPZ; 10; HH1; Rata Peaks, NZ (South-North); 1; 4
NZ; RPZ; 10; HH2; Rata Peaks, NZ (West-East); 1; 4

These are very high sample-rate signals (100 samples per second), so the seismograms's file size is large. At the full sample rate, these files take a while to download and a while to process and display. Consider setting the sample rate to 10 samples per second (a factor of 10 decrease in file size). Decimating signals puts a load on the IRIS seismogram servers but most of the information at the highest frequencies is lost because of the distance the seismometer is from the earthquakes, so you aren't missing any signal.

Here's an image with a 15 minute duration. The fifteen-minute seismograms are about 36k each.

Friday
Dec162011

The Central United States

The New Madrid Earthquake Sequence Anniversary

The 200th anniversary of the New Madrid Earthquake Sequence starts the 16th of December (the sequence included three large events between December 1811 and February 1812).

The 1811-12 New Madrid earthquake sequence was dominated by three large shocks. Although we don't know the exact locations of the events, we can estimate their positions using information contained in local accounts and newspaper descriptions. Post-1974 seismicity is shown with gray circles and they nicely outline the main structures in the New Madrid Fault System.

Here's a set of vertical component channels that record ground motions near the New Madrid Seismic Zone. The filters are set to enhance local seismicity.

NM; UALR; --; BHZ; University of Arkansas, Little Rock, AR, USA; 0.5; 2
NM; PBMO; --; BHZ; Three Rivers Community College, Poplar Bluff, MO, USA; 0.5; 2
NM; PVMO; --; BHZ; UM Delta Research Portageville, MO, USA; 0.5; 2
TA; V44A; --; BHZ; Blytheville, AR, USA; 0.5; 2
NM; UTMT; --; BHZ; UT Martin, TN, USA; 0.5; 2
NM; SIUC; --; BHZ; UM Carbondale, IL, USA; 0.5; 2
NM; BLO; --; BHZ; UI Bloomington, IN, USA; 0.5; 2
TA; W45A; --; BHZ; Hickory Valley, TN, USA; 0.5; 2

You can find more information on the earthquake sequence from the USGS here, or from the University of Memphis' CERI (Memphis, TN) here, or from the Saint Louis University Earthquake Center here.

Monday
Nov282011

A Sample of the EarthScope Transportable Array

EarthScope is a large, U.S. National-Science-Foundation funded project to study the Earth's structure beneath North America, to monitor plate boundary deformation using geodetic and seismic observations, and to sample the shallow portion of the San Andreas Fault near Parkfield California. You can read the details at http://www.earthscope.org.

Part of the EarthScope project is USArray, which includes a large network of seismometers that is slowly migrating across the conterminous US from west to east. Right now, the network is in the midwest, as shown in the following map from http://usarray.org.

 

The following channel list includes vertical component Transportable Array Seismometers arranged from north to south from Wisonsin to Louisiana.

TA; E41A; --; BHZ; Kenton, WI
TA; I42A; --; BHZ; Ripon, WI
TA; M43A; --; BHZ; Utica, IL
TA; Q44A; --; BHZ; Vandalia, IL
TA; U44A; --; BHZ; Hornbreak, TN
TA; X45A; --; BHZ; Abbeville, MS
TA; 246A; --; BHZ; Bay Springs, MS
TA; 646A; --; BHZ; Port Sulfur, LA

The sample rate for these channels is 40 samples per second, so displaying the seismograms tasks my iPad 1 with IOS 5 - a refresh after rotating the screen, rescaling, etc. takes about 10 seconds.

Friday
Nov182011

Detecting Aftershocks of the 18 November, 2011 Washington Earthquake 

The first station (Colville Reservation, Omak, WA) is very close to the earthquake. You should see the smallest earthquakes on Omak, WA. Larger aftershocks will be visible on the more distant stations at Davenport and Marblemount, WA. Sometimes a station may experience a data transmission delay that we call latency, so the most recent signals are not available.  At least at the time of this posting, the latency of data from OMAK is more than 30 minutes.

UW; OMAK; --; BHZ; Omak, WA (Up-Down); 0.8; 5.0
UW; OMAK; --; BHE; Omak, WA (East-West); 0.8; 5.0
UW; OMAK; --; BHN; Omak, WA (North-South); 0.8; 5.0
UW; DAVN; --; BHZ; Chrisman Ranch, Davenport, WA (Up-Down); 0.8; 5.0
UW; DAVN; --; BHE; Chrisman Ranch, Davenport, WA (East-West); 0.8; 5.0
UW; DAVN; --; BHN; Chrisman Ranch, Davenport, WA (North-South); 0.8; 5.0
UW; MRBL; --; BHZ; Marblemount, WA (Up-Down); 0.8; 5.0
UW; MRBL; --; BHE; Marblemount, WA (East-West); 0.8; 5.0
UW; MRBL; --; BHN; Marblemount, WA (North-South); 0.8; 5.0

The sample rate for these channels is 40 samples per second, so displaying the seismograms tasks my iPad 1 with IOS 5 - a refresh after rotating the screen, rescaling, etc. takes about 10 seconds.

Saturday
Nov052011

Detecting Aftershocks of the 05-06 November, 2011 Oklahoma Earthquakes

The first station (Meyer Ranch, OK) is very close to the earthquakes, the second station (Tecumseh, OK) is close, the third is farther west (Wichita Mountains, OK). You should see the smallest earthquakes on Meyer Ranch and perhaps also on Tecumseh. Larger aftershocks will be visible on all three stations.

Sometimes a station may experience a data transmission delay that we call  latency, so the most recent signals are not available.  The sample rate for these channels is 40 samples per second, so displaying the seismograms tasks my iPad 1 with IOS 5 - a refresh after rotating the screen, rescaling, etc. takes about 10 seconds.

TA; V35A; --; BHZ; Meyer Ranch, Chandler, OK (Up-Down); 0.8; 5.0
TA; V35A; --; BHE; Meyer Ranch, Chandler, OK (East-West); 0.8; 5.0
TA; V35A; --; BHN; Meyer Ranch, Chandler, OK (North-South); 0.8; 5.0
TA; W35A; --; BHZ; Tecumseh, OK (Up-Down); 0.8; 5.0
TA; W35A; --; BHE; Tecumseh, OK (East-West); 0.8; 5.0
TA; W35A; --; BHN; Tecumseh, OK (North-South); 0.8; 5.0
US; WMOK; 00; BHZ; Wichita Mountains, OK (Up-Down); 0.8; 5.0
US; WMOK; 00; BH2; Wichita Mountains, OK (East-West); 0.8; 5.0
US; WMOK; 00; BH1; Wichita Mountains, OK (North-South); 0.8; 5.0

The earthquake occurred just west of the EarthScope (http://www.earthscope.org) Transportable Array, a large temporary network of seismometers that are currently installed in the central Conterminous United States. You can see a map of the network here, and you can view the ground motion animation by clicking here

If you look at individual events, a few minutes is all you need to see the signals at all three stations. For small aftershocks, even 1.5 minutes duration is sufficient. Here's a plot of the signals for a magnitude 2.7 aftershock:

If you monitor the signals, you might use about a 15 minute duration if you are using more than one station; or 30 minutes if you just look at the closest (example below).

Friday
Oct282011

Detecting Aftershocks of the 28 October, 2011 Peru Earthquake

The closest publicly accessible near-real-time station is NNA, located in Nana, Peru, about 300-350 km from the earthquake. 

II; NNA; 00; BHZ; Nana, Peru (Up-Down); 0.2; 5.0
II; NNA; 00; BH2; Nana, Peru (East-West); 0.2; 5.0
II; NNA; 00; BH1; Nana, Peru (North-South); 0.2; 5.0
Thursday
Oct272011

Detecting Aftershocks of the 27 Oct, 2011 Mw 4.7 Northern California Earthquake

This earthquake occurred withing the Western Great Basin Seismic Network, which is operated by the USGS and the University of Nevada, Reno. Several stations are very close to the epicenter.  You can watch for aftershocks using the northern california channel set, or this collection which adds some of the close stations. The sample rate for the close stations is high, try about 10 minutes for a duration. I've noticed noticeable slow downs on my iPad1 running IOS5 (especially in the plotting).

NN; BEK; --; EHZ; Beckworth, CA (Z); 0.5; 10;
NN; LOY; --; EHZ; Loyalton, CA (Z); 0.5; 10;
NN; SAT; --; EHZ; Sattley, CA (Z); 0.5; 10;
NN; IND; --; EHZ; Independence, CA (Z); 0.5; 10;
BK; WDC; 00; BHZ; Whiskeytown, CA, USA (Z); 0.5; 5;
BK; CMB; 00; BHZ; Columbia, CA, USA (Z); 0.5; 5;