Merging transfrontier internet macroseismic data of earthquakes in NW Europe using a grid cell approach Koen VAN NOTEN*, Thomas LECOCQ , Thierry CAMELBEECK Seismology-Gravimetry, Royal Observatory of Belgium, Brussels, Belgium *now at Geological Survey of Belgium, Royal Belgian Institute of Natural Sciences
Klaus-G. HINZEN Erdbebenstation Bensberg, Cologne University, Bergisch Gladbach, Germany
Christophe SIRA Le Bureau Central Sismologique Français, Strasbourg, France
[email protected] @koen_vannoten
Workshop Workshopon oninternet internetmacroseismology macroseismology––Lublijana, Lublijana,15/11/ 15/11/2017 2017
Belgium: A long history in Macroseismology Nederland
Deutschland
France
Orp-Jauche 1828, MS 4.6, P.N.G. Egen
Luxem b o u rg
Workshop on internet macroseismology – Lublijana, 15/11/2017
1938, Ms 5.0 – Zulzuke-Nukerke Earthquake
Intensity data of Somville 1939 re-evaluated to EMS98
First Macroseismic survey in Belgium
Photo: Lille (FR)
Workshop on internet macroseismology – Lublijana, 15/11/2017
2002, ML 4.9 – Alsdorf, Germany
First online macroseismic survey in Belgium by T. Camelbeeck and colleagues Questionnaire based on Wald et al. 1999 Alsdorf: most successful survey with 6192 forms from BE France
Workshop on internet macroseismology – Lublijana, 15/11/2017
Overview of 15 years (2002-2017) online macroseismology • Felt Earthquakes: 206 • • • •
Total number of forms: 32.344 Most for a single event: ML 4.9 Alsdorf: 6192 forms Highest Magnitude: ML= 5.4 (Rambervillers - FR) Lowest Magnitude: ML= 0.3 (36(15) forms: Swarm central BE)
Hour Van Noten et al. 2015 – Tectonophysics 656, 20-38 Workshop on internet macroseismology – Lublijana, 15/11/2017
Since 2010: ROB-BNS shared form & maps
R O B S E R V E R S
B N S
MySQL server
Macro maps
No app but mobile website
Macro maps
S E R V E R S
Intensity quality rather then quantity
Workshop on internet macroseismology – Lublijana, 15/11/2017
Since 2014: ROB-BCSF collaboration
http://seisalert.oma.be/dyfi/
Workshop on internet macroseismology – Lublijana, 15/11/2017
Since 2014: ROB-BCSF collaboration
Mean intensity vs local observations
http://seisalert.oma.be/dyfi/
Workshop on internet macroseismology – Lublijana, 15/11/2017
2011, ML 4.3 Goch earthquake, Germany
Classical community intensity map
ROB-RNS: 3294 forms Workshop on internet macroseismology – Lublijana, 15/11/2017
Fragmentation of macroseismology in Europe 3000 km
? ? ? ?
?
? ? ?
34 institutes 24 countries
? ? ?
“Earthquakes don’t stop at political/language borders”
Van Noten et al. 2017, Solid Earth 8(2)
Workshop on internet macroseismology – Lublijana, 15/11/2017
Workshop on internet macroseismology – Lublijana, 15/11/2017
2011, ML 4.3 Goch earthquake, Germany
Quality of “shared” data ? ROB-BNS: KNMI: NRW-GD EMSC: USGS:
Location
Intensity algorithm
street address thrust in sharing - street address truncated to 3 digits: precise to 0.1 km location truncated to 2 digits: precise to 1.1 km
Wald et al. 1999: CDI Wald et al. 1999: CDI Indiv. Quest., 0.5 intensity units Thumb. (int) & Quest. (0.1 digit) Wald et al. 1999: CDI
Workshop on internet macroseismology – Lublijana, 15/11/2017
Correcting intensity for floor level
Workshop on internet macroseismology – Lublijana, 15/11/2017
True address geocoding to improve location Problems with official address geocoding services: People are lazy: errors, abbreviations in written address “ARSO, Vjjkvoa cestta 1b, 1000 Ljblja, Slovenia”
The google api json file http://maps.googleapis.com/maps/api/ geocode/json?address=“Vjjkvoa cestta 1b, 1000 Lublijana, Slovenia“%s&sensor=false
Output: Correct address: Vojkova cesta 1b Geolocation: 46.0664, 14.5148 Quality control: ROOFTOP Epicentral & hypocentral distances ROOFTOP, RANGE_INTERPOLATED, GEOMETRIC CENTER, NO ADDRESS APPOXIMATE Workshop on internet macroseismology – Lublijana, 15/11/2017
Grid cell intensity assessment
Grid cell analysis of 60 – 90 % data
Workshop on internet macroseismology – Lublijana, 15/11/2017
2011, ML 4.3 Goch earthquake, Germany
Workshop on internet macroseismology – Lublijana, 15/11/2017
Grid cell intensity comparison
Workshop on internet macroseismology – Lublijana, 15/11/2017
COMPARISON OF MACROSEISMIC QUESTIONNAIRES USED IN VAN NOTEN ET AL. (2017), Solid Earth, 8, 453-477. Nr.
Questions
Possible answers
ROB-BNS
BCSF
KNMI
NRW-GD
BGS
EMSC
USGS
1
Date and Time
yes
yes
yes
yes
yes
yes
yes
2
Street, Address
yes
yes
yes
yes
yes
yes
yes
3
Zip code, City, Country
yes
yes
yes
yes
yes
yes
yes
no
no
no
no
no
yes
no
yes
yes (less precise)
yes
yes
yes
yes
yes
no
no
no
yes
no
no
no
yes
no
no
yes
no
no
no
PERSON'S SITUATION WHEN THE EARTHQUAKE OCCURRED 4 How many times have you felt an earthquake ?
1st, few times, often No answer / Inside / Outside / In a stopped vehicle / In a moving vehicule / other church tower / electricity mast / scaffolding
5
What was your situation during the earthquake?
6
What was your situation during the earthquake?
7
No building, Family home, Apartment building, If you were inside, please select the type of building Office building/school, Mobile Home with or structure permanent foundation / Trailer without fundation
yes
yes
yes
partly
8
At what floor where you?
Inside / Outside / Groundfloor / Floor number
yes
=5
yes
yes*
9
Type (wood, brick, etc.) of the building
wood / brick / concrete / loam / …
yes
yes
yes
yes
10
Height (in floors) of the building
specify
yes
yes
yes
no
no
no
no
11
Type of activity during event
Standing, sitting, lying, walking, kneeling, sleeping
no
yes
no
yes
yes
yes
no
12
Swinging effect of the respondent
Standing up, swaying, fell
no
yes
no
yes
no
yes
no
0,1,2,3,48,>8 Yes
PERCEPTION OF THE EARTHQUAKE 13
Did you feel the earthquake?
no / yes
yes
yes
yes
yes*
yes
yes
yes
14
Were you asleep during the earthquake?
no / yes, didn't get up / yes, did get up
yes
yes
yes
yes
yes
yes
yes
15
What best describes any sound you heard?
no sound / rumblinb / roaring / explosion
no
yes
no
yes
yes
yes
no
16
Did you hear a noise? How loud ?
no / yes, slight, loud noise
yes
yes
no
yes*
yes
yes
yes
17
Did you hear church bells ?
no / yes
no
no
no
yes
no
yes
no
18
Did other persons nearby feel the earthquake?
I don't know, nobody nearby/some felt it, others not/most felt it, others not/(almost) everone felt it
yes
no
yes
yes
yes
yes
yes
19
Have you felt shocks before or after, if so how long/many
Specify
no
YES (last case observations)
no
yes
no
no
no
yes
yes
yes
yes*
yes
yes
yes
YOUR EXPERIENCE OF THE EARTHQUAKE 20
How would you best describe the ground shaking?
weak / mild / moderate / strong / violent
21
How would you describe the earthquake shaking
vibrating / trembling / swaying / impact / rolling
no
yes
no
yes
yes
yes
no
22
About how many seconds did the shaking last?
yes
no
yes
yes
no
no
no
23
How would you best describe your reaction?
yes
yes
yes
yes*
yes
yes
yes
24
How did you respond?
Specify no reaction / very little reaction / excitement / (somewhat, very, extreme) frightened No action / moved / cover / ran outside
yes
yes
yes
yes*
yes
no
yes
25
Was it difficult to stand or walk?
no / yes (difficult, fallen, forcibly thrown)
yes
yes
yes
yes*
no
no
yes
ROB-BNS
BCSF
KNMI
NRW-GD
BGS
EMSC
USGS
Nr.
Questions
Possible answers
EARTHQUAKE EFFECTS ON FURNATURE AND BUILDING 26
Did you notice the swinging or swaying of doors, windows or free-hanging objects?
27
Did you notice creaking or other noises?
No answer, did not look / yes (slight/violent swinging) No answer, paid no attention / yes (slight/loud
yes, only yes yes yes checkbox Workshop on internet macroseismology – Lublijana, 15/11/2017 yes, only yes yes yes no no yes yes
yes (only objects)
yes
2011, ML 4.3 Goch earthquake, Germany Grid cell intensity map
ZIP-CIIM
n = 10.2k
n = 8.4k
Workshop on internet macroseismology – Lublijana, 15/11/2017
2015, ML 4.2 Ramsgate earthquake, UK
Workshop on internet macroseismology – Lublijana, 15/11/2017
Intensity attenuation of grid cell maps
Individual intensity
Smoothed IARs moving bin Lw of 20 km steps of 2 km CEUS A&W2007
Grid Cell intensity
Workshop on internet macroseismology – Lublijana, 15/11/2017
Both EQ show deviations from concentric Isoseismals !
GEOLOGY ! • Bedrock depth determines how we perceive these earthquakes • High Q – along the strike of a tectonic structure • Low Q – perpendicular to this structure
Van Noten et al. 2017 – Solid Earth Workshop on internet macroseismology – Lublijana, 15/11/2017
Conclusions • Mapping cities or entire regions using grid cells is a nice parallel to ZIP-CIIM maps • Benefits of using grid cell maps: A solution for macroseismic data exchange in Europe? + less subjective – homogeneous intensity distribution + no personal information shared + no problems with truncated coordinates & geocoding + no problems with badly reported response addresses + different intensity approaches can be merged + based on open-source software + reliable attenuation models using grid cell intensity • Risk in using grid cells & merging data from different questionnaires ? - merging intensities and not the grouped answers - as long questionnaires are not homogenised, we cannot do better - double entries ? • Macroseismology: not just a matter of MAPPING • Case study: Intensity distribution of the two M4 earthquakes strongly depends on regional geology, earthquake magnitude and source depth. Project funded by
Ljubljana, 14/11/2017
Workshop on internet macroseismology – Lublijana, 15/11/2017
