Today's and yesterday's temperature.
This is the recent raw output of our seismograph station. please see the Seismology section for a list of earthquakes detected earlier. Please note the date is indicated on the top left of the graph and the time is the universal time UTC.
I am located in Quebec city, Canada. (FN46IS) Recently I built a
seismometer, which I operate in the basement of my house.
It took 22 months to design and build the instrument. Not a
geologist, I had to read documents and make many choices for my
first design. The instrument is in continuous operation since
February 2021. It has captured some vibrations from
distant earthquakes as well as one "local" event (M3.9). See
below the seismograms for some events that I could identify using USGS Wilber. 
I have a Geiger counter in continuous operation. Its output is
periodically reported to the radmon.org
surveillance network. You can see the background radiation level
on the map. My station is labelled amichaud in the list. However you can
go directly to my (hourly) report and graph on their site by
following the link here.
Count rate below 20 CPM is normal for my staion.
Unlike other stations in this network, the numbers that is upload
from my station represent the number of counts per minutes (CPM)
that has already been averaged over a period of one hour. I only
upload one number every hour in order to save network bandwidth. I
believe this is the reason why the long time plots have a
different look for this station.
COORD: 8.5266 °N, 126.4487 °E, 2023-12-02 14:37:03 UTC, 32.763 km, mww7.6, Mindanao, Philippines.
COORD: 6.456 °S, 129.5134 °E, 2023-11-08 04:53:51 UTC, 10.0 km, Mww7.1 Banda Sea.
COORD: 6.3817 °S, 129.7785 °E, 2023-11-08 04:52:52 UTC, 10.0 km, Mwb6.7 Banda Sea.
COORD: 39.3568 °N, 48.199 °E, 2023-11-08 05:18:48 UTC, 52.562 km, mb4.8 Armenia-Azerbaijan-Iran Bord Reg.
COORD: 6.1903 °S, 129.9158 °E, 2023-11-08 05:42:39 UTC, 10.0 km, mb5.1 Banda Sea.
COORD: 6.4133 °S, 129.9523 °E, 2023-11-08 06:06:52 UTC, 10.0 km, mb5.1 Banda Sea.
COORD: 6.5339 °S, 129.5949 °E, 2023-11-08 06:57:48 UTC, 10.0 km, mb4.6 Banda Sea.
COORD: 31.622 °N, 103.982 °W, 2023-11-08 10:27:49 UTC, 7.417 km, ML(TexNet)5.2 Western Texas.
COORD: 31.613 °N, 103.994 °W, 2023-11-08 10:30:06 UTC, 7.5841 km, ML(TexNet)3.2 Western Texas.
COORD: 6.302 °S, 129.474 °E, 2023-11-08 10:43:38 UTC, 10.0 km, mb4.7 Banda Sea.
COORD: 12.814 °N, 88.1265 °W, 2023-07-19 00:22:07 UTC, 69.727 km, mww6.5 Off Coast Of Central America.
The seismometer is in the basement of our house located in the city center. The street is right in front of the house and the distance between the seismometer and the trafic is about sixty feet. The solid rock is probably less than twenty feet below the surface. We sometimes worried if the local trafic show on our seismograms. It is possible that some of the noise is due to the to trafic and local sources, but we could never see a one-to-one correlation with a known local event. Today we can.
At 8h00 local time this morning (12h00 UTC) an excavator came right in front of the house and they removed the asphalt. They also removed the sand under the ashalt and replaced it by some new one. The excavator compacted the sand and they also brought a vibrating machine (man operated) in order to compact it even more. This operation lasted three hours until noon (14h00 UTC). At 11h00 (15h00 UTC) they were gone for lunch and the place was dead quiet until a second team came at 14h00 (16h00 UTC) to put some new asphalt. This hapened when you see the large spikes on the plot. They last until 15h00 (19h00 UTC), that's when they were gone for the week-end.
OBSERVATION: During the morning, when they were digging and compacting the sand by hitting on it "bang bang bang" using the excavator bucket and when they were vibrating the soil, we observed nothing! In the past, I have always assumed that high frequency vibrations associated to local noise are outside the passsband of the instrument this can not be seen by the instrument. But today this is an extreme case, even an excavator taping the ground in the street does ont show on the plot.
However during the afternoon, when they put the asphalt and the roller-compactor was moving on it back-and-forth, again and again, in silence, then we can see those giant spikes. I was sitting in the window and I saw the road roller, there is no doubt that its movement correspond to the spikes on the plot and it shows that the seismograph is far more sensitive to the low frequencies.
In my opinion, limiting the passband of the instrument by shutting the hig frequencies was an important factor in the design of the instrument, otherwise local noise sources could be a limiting factor.
Finally I would like to mention that the larger spikes are pointing up then the distribution function does not seem symetrical.
COORD: 28.7471 °S 71.5702° W, 2023-10-31 12:33:43 UTC, 35.0 km, mww6.6, Near Coast Of Central Chile.
COORD: 50.7956 °N, 130.2988 °W, 2023-09-17 11:28:11 UTC, 10.0 km, Mww5.6, Vancouver Island, Canada Region.
COORD: 31.1095 °N, 8.4404 °W, 2023-09-08 22:11:01 UTC, 18.535 km mww6.8 Morocco.
also:COORD: 19.4171 °N, 104.935 °W, 2023-09-08 16:37:16 UTC, 53.694 km, mww5.8, Near Coast Of Jalisco, Mexico.
also:COORD: 19.4487 °N, 105.0212 °W, 2023-09-08 15:53:22 UTC, 35.024 km, mww5.6, Near Coast Of Jalisco, Mexico.
A powerful 6.8-magnitude earthquake struck Morocco Friday night, killing nearly 2700 people and damaging buildings in the historic city of Marrakech in what the United States Geological Survey (USGS) said was the strongest tremor to hit that part of the North African nation in more than a century.
COORD: 6.7876 °S, 116.548 °E, 2023-08-28 19:55:31 UTC, 513.545 km, Mww7.1 Bali Sea.
COORD: 12.814 °N, 88.1265 °W, 2023-07-19 00:22:07 UTC, 69.727 km, mww6.5 Off Coast Of Central America.
COORD: 54.4596 °N, 160.7604 °W, 2023-07-16 06:48:22 UTC, 32.571 km, mww7.2, Alaska Peninsula.
COORD: 15.0337 °N, 93.8771 °W, 2023-07-14 09:29:01 UTC, 35.0 km, mww6.3, Near Coast Of Chiapas, Mexico.
COORD: 20.0437 °N, 61.0833 °W, 2023-07-10 20:28:25 UTC, 10.0 km, mww6.6, North Atlantic Ocean.
COORD: 23.2433 °N, 108.6306 °W, 2023-06-18 20:30:22 UTC, 10.0 km, mww6.4, Gulf Of California.
This section summarizes the instument drift for the last two an a half years. We ask the reader to closely follow the plot "Temperature [C], DC output [V] vs Time [h]" found on this page, as we give a complete description of the operation since it was put into operation. Please note that all the images in this page can be enlarged by opening them in a separate tab or window (right click on the image).
During the month of January 2021, the seismometer was operated on a table while various tests were done. Once it was found that the instrument was ready to be commissioned, it was transported to the permanent site, located 7 meters away, on the concrete floor, near the corner of the home basement. After the move the instrument zero had not significantly changed, therefore it was not necessary to reset it. As soon as the instrument was in the new position, it was turned on and the data logging was started. This event is pointed by the arrow labeled: "Start: Jan 30, 2021".
The purple line represent the temperature. The sensor is located inside the seismometer, on the frame.
The green line shows
the the feedback loop filter output. This output is sometimes
called "mass position"
representing where the mass would go if the restoring force was
removed and it was freely floating. Because it is a DC coupled
signal, it is contaminated by integrator drift, metal fatigue and
temperature effects, therefore its use is mainly for diagnostic purpose. Obviously
this signal should never go over range. We monitor this output and
we reset the mass position
on the beam as required. This is easily done in-situ using the remote
controlled motorized mass positioner.
Both the temperature and integrator output are sampled for a
period of one minute at the end of every hour. The average is
represented by one data point on the plot.
Start: Jan 30, 2021. As soon as the instrument is in position on the floor, we see the temperature going down and the drift appear.
A day or two after the "start" point we installed a thick thermal insulation jacket and a wood/Styrofoam enclosure around the instrument. Immediately after (one day) the temperature jumps up by almost two degrees. One can see on the plot the correlation between the temperature and the integrator output.
During the winter months, the temperature is more stable due to electric heating of the house. Please note that there is NO active temperature stabilization of the instrument itself or the thermal jacket or even the enclosure.
During the summer months the temperature slowly raises. The blip in April could be due to the ground around the house that unfreezes, or the house heating stops. The temperature is measured inside the instrument located on the concrete floor, while the temperature control for the room is at 1.5 meter high on the wall as well as the electric plinth.
In May, and June 2021, the data acquisition stopped on two occasions due to software bugs. However the instrument stayed ON and there was no major effect.
The July 2021 event: The instrument was left unattended for a couple of weeks. The data acquisition stopped due to a software bug. When we restarted the acquisition, we falsely believed that the instrument had gone over range, therefore we moved the mass position using the remote control. We will see that this was not the case but please observe the green dot, as the acquisition was restarted, then the new voltage value as we moved the mass to its new position.
Then we had a normal operation for two months until September 2021. Please observe
a short flat section that looks like a saturation again! At this
moment, the mass seemed to have reached the base-of-the-boom limit
position and we had no other choice to open the instrument and
shorten the spring so the mass can be re-positioned on the center
of the boom. Also, the clamp that hold the spring in place was
properly tightened. All these operations: opening the instrument
cover, adjusting the spring, tightening the clip and closing the
cover and the enclosure was done on the floor, without moving the
instrument and took less than one hour. During that period, the
data acquisition was NOT stopped. This September 2021 event shows
an extra faster time constant
glitch due to the temperature change inside the instrument.
During the almost three year period covered by the plot, this was
the only occasion when we had to open the instrument, or the
temperature jacket/enclosure. [Update]:
It appears, that this should not be necessary for another year.
In November 2021, again we believed we had to move the mass. This time we gained some confidence and we kept these settings for ten months.
At the end of August 2022 we move the mass one more time. This time it will last for four months.
At the end of December 2022 we moved the mass again. At this point, we believe that the mass is slowly reaching the base-of-the-boom limit position. One or two more mass repositioning, and we will have to open the instrument again to reset the spring length.
In conclusion, after two and a halt years of continuous operation, it seems that the slow drift is constant. Although there is a dependence with the temperature, its effect is smaller than the drift. The drift is in the same direction as if the spring or the Nylon twine holding the boom are slowly stretching.
COORD: 8.9283 °N, 77.0881 °W, 2023-05-25 03:05:33 UTC, 13.0 km, mww6.5, Panama-Colombia Border Region.
COORD: 23.0622 °S, 170.4562 °E, 2023-05-20 01:51:01 UTC, 35.981 km, mww7.1, Southeast Of Loyalty Islands.
COORD: 23.1852 °S, 170.7633 °E, 2023-05-19 02:57:03 UTC, 18.027 km, mww7.7 Southeast Of Loyalty Islands.
COORD: 15.6002 °S, 174.6077 °W, 2023-05-10 16:02:00 UTC, 210.097 km, mww7.6, Tonga Islands
COORD: 29.9676 °S, 177.8264 °W, 2023-04-24 00:41:55 UTC, 43.063 km, mww7.1, Kermadec Islands, New Zealand.
COORD: 0.781 °S, 98.5339 °E, 2023-04-24 20:00:55 UTC, 15.462 km, Mww7.1, Southern Sumatra, Indonesia.
COORD: 6.0255 °S, 112.0332 °E, 2023-04-14 09:55:45 UTC, 594.028 km, mww7.0, Java, Indonesia.
COORD: 49.2066 °N, 129.6203 °W, 2023-04-13 15:54:53 UTC, 7.275 km, mww6.0, Vancouver Island, Canada Region.
COORD: 38.0726°N, 73.2077°E, 2023-02-23 00:37:40 UTC, 20.522 km, Mww6.8, Tajikistan-Xinjiang Border Reg.
I am very sorry to report the strongest earthquake that was ever recorded in Turkey and Syria. Twenty hours after the seism, the news channels are reporting a death count above 4300.
Three weeks later the death count was at 50300.
The first quake was the strongest one:
COORD: 37.1736 °N, 37.032 °E, 2023-02-06 01:17:35 UTC, 17.925 km deep, mww7.8, Turkey.
Acording to the experts, the devastation is due to the short distance to the surface (20 km).
The earthquake was immediately followed by a much smaller one, not visible on our plot:
COORD: 37.1272 °N, 36.9426 °E, 2023-02-06 01:28:15 UTC, 14.497 km deep, Mww6.7, Turkey.
As often the case, there was an echo; this time almost as strong as the original earthquake:
COORD: 38.0235 °N, 37.203 °E, 2023-02-06 10:24:49 UTC, 10.0 km deep, mww7.5, Turkey
COORD: 40.525°N, 124.423°W, 2022-12-20 10:34:24 UTC, 17.91 km, mw6.4 Near Coast Of Northern Calif.
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This is the completed seismometer. It was put in operation in
january 2021. A description will be posted here.
| This page is a personal web page
related to SEISMOLOGY as a HOBBY. This means
that this page has not been peer reviewed, as well
as it is not endorsed by any official or commercial
organization. In effect, it has no scientific value! I am a retired electrical engineer, and my skills are related to building and using high precision measuring instruments, building atomic clocks, and tunable lasers. I also participated to fundamental research in laser spectroscopy, a physics science called "laser cooling and trapping", and also "Bose-Enstein Condensation". I also designed and built "Atomic Clocks". These are high performance time-keepers. I built several prototypes of those. Finally I was responsable for a Microwave Metrology Laboratory. I also published my research in scientific journals. As I just explained, I had no formal training or experience in geology or earth sciences. I am only an AMATEUR in this field! If you are uncertain, please do not use the information presented on this page. On the opposite side, I should mention that I do not receive any amount of money and I do not comment on any organization, any other result or any comercial product. If you find any indication of the opposite please accept my apology and let me know so I can quickly correct the mistake. My objective is show that it is possible to build functional measuring instruments using modest resources, while having fun! |