Dr. Ing. Jorge E. Alva Hurtado
Mag. Ing. Carmen Ortiz Salas
Dr. José Macharé O.
Ing. Jorge Soto Huamán
www.jorgealvahurtado.com
www.red-acelerografica-peru.com
THE EFFECTS OF THE 26/05/19 LAGUNAS EARTHQUAKE ON THE PERUVIAN JUNGLE
Tectonic setting
Peak GroundAcceleration (m/s2)
Peru seismicity
MAXIMUM SEISMIC INTENSITIES (Alva et.al, 1984)
Seismic hazardMAX PGA 10% EXC, 10-YEARS (Gamarra, 2009)
The Lagunas earthquake 26/05/2019
Data Source
Geographical
Depth (Km)Hora
EpicentralUTC
coordinates (°)
Latitude Longitude
South West
IGP -5.740 -75.550 135.0 07:41:12
USGS -5.796 -75.298 109.9 07:41:14
The Lagunas earthquake: tectonic process
Accelerometric data:
gathering and analysis
- Recording in 60 stations
- Several institutional networks
- Accurate análisis
LEGEND
Station
Station
Station
Station
Epicenter
Epicenter
ACELEROGRAMA ESTACIÓN SENCICO-CISMID IQUITOS
GROUND MOTION RECORD, V COMPONENT
SEISMIC STATION UNTRM
SEISMIC STATIONCIP CIP MOYOBAMBASEISMIC STATION SENCICO – CIISMID IQUITOS
SEISMIC STATION CIP TARAPOTO
SEISMIC STATION UNJ
SEISMIC STATIION CIP AMAZONZAS
LEGEND
Station CIP UNI
Epicenter USGS
Epicenter IGP
Station SENCICO - CISMID
Time (sec)
Acc
ele
rati
on
(cm
/s2)
Time (sec)
Acc
ele
rati
on
(cm
/s2 )
Time (sec)
Acc
ele
rati
on
(cm
/s2 )
Time (sec)
Acc
ele
rati
on
(cm
/s2 )
Time (sec)
Acc
ele
rati
on
(cm
/s2 )
Time (sec)
Acc
ele
rati
on
(cm
/s2 )
ACELEROGRAMA ESTACIÓN SENCICO-CISMID IQUITOS
GROUND MOTION RECORD, NS COMPONENT
SEISMIC STATION UNTRM
SEISMIC STATIONCIP CIP MOYOBAMBASEISMIC STATION SENCICO – CIISMID IQUITOS
SEISMIC STATION CIP TARAPOTO
SEISMIC STATION UNJ
SEISMIC STATIION CIP AMAZONZAS
LEGEND
Station CIP UNI
Epicenter USGS
Epicenter IGP
Station SENCICO - CISMID
Time (sec)
Acc
ele
rati
on
(cm
/s2)
Time (sec)
Acc
ele
rati
on
(cm
/s2 )
Time (sec)
Acc
ele
rati
on
(cm
/s2 )
Time (sec)
Acc
ele
rati
on
(cm
/s2)
Time (sec)
Acc
ele
rati
on
(cm
/s2)
Time (sec)
Acc
ele
rati
on
(cm
/s2 )
Time (sec)
Acc
ele
rati
on
(cm
/s2 )
Time (sec)
Acc
ele
rati
on
(cm
/s2 )
Time (sec)
Acc
ele
rati
on
(cm
/s2 )
Time (sec)
Acc
ele
rati
on
(cm
/s2)
Time (sec)
Acc
ele
rati
on
(cm
/s2)
Time (sec)
Acc
ele
rati
on
(cm
/s2 )
GROUND MOTION RECORD, EWCOMPONENT
ACELEROGRAMA ESTACIÓN SENCICO-CISMID IQUITOS
SEISMIC STATION UNTRM
SEISMIC STATIONCIP CIP MOYOBAMBASEISMIC STATION SENCICO – CIISMID IQUITOS
SEISMIC STATION CIP TARAPOTO
SEISMIC STATION UNJ
SEISMIC STATIION CIP AMAZONZAS
LEGEND
Station CIP UNI
Epicenter USGS
Epicenter IGP
Station SENCICO - CISMID
Time (sec)
Acc
ele
rati
on
(cm
/s2)
Time (sec)
Acc
ele
rati
on
(cm
/s2 )
Time (sec)
Acc
ele
rati
on
(cm
/s2 )
Time (sec)
Acc
ele
rati
on
(cm
/s2)
Time (sec)
Acc
ele
rati
on
(cm
/s2)
Time (sec)
Acc
ele
rati
on
(cm
/s2 )
Maximum Peak Ground
Accelerations recorded
LEGEND
Station
Station
Station
Station
Epicenter
Epicenter
PEAK GROUND ACCELERATIONS OF MOTION RECORD IN PERU,
ACCELEROGRAPHIC NETWORK: CIP AND UNI
N° INSTITUTION STATION LOCATIONEPICENTRAL
DISTANCE (KM)
TYPE OF SOILPEAK VALUE, WITH CORRECTION (cm/seg²) MAXIMUN PEAK
VALUE(cm/seg²)
MAXIMUN PEAK VALUE
(g)PGA EO PGA NS PGA V
1POSGRADO FIC UNI / UNTRM
UNTRMAMAZONAS,
CHACHAPOYAS, CHACHAPOYAS
292HIGH
COMPRESSIBILTY CLAY
95.84 87.45 53.49 95.84 0.096
2 CIPCIP
MOYOBAMBA
SAN MARTIN, MOYOBAMBA, MOYOBAMBA
192 CLAY 91.29 78.76 90.16 91.29 0.093
3 CIP CIP TARAPOTOSAN MARTIN, SAN
MARTIN, TARAPOTO153
HIGH COMPRESSIBILTY
CLAY58.18 79.56 67.86 79.56 0.081
4 CIP CIP AMAZONASAMAZONAS,
CHACHAPOYAS, CHACHAPOYAS
294HIGH
COMPRESSIBILTY CLAY
78.91 53.98 53.05 78.91 0.08
5POSGRADO FIC
UNIPACASMAYO
LA LIBERTAD, PACASMAYO, PACASMYO
529 GRAVEL SANDY 38.07 25.02 17.99 38.07 0.039
6POSGRADO FIC
UNIUNJ CAJAMARCA, JAEN, JAEN 391
POORLY GRADED GRAVEL
29.24 32.60 19.23 32.60 0.033
7POSGRADO FIC
UNIUNC
CAJAMARCA, CAJAMARCA, CAJAMARCA
391 CLAYEY SILT 25.26 22.63 17.09 25.26 0.025
8 CIP CIP LA LIBERTADLA LIBERTAD, TRUJILLO,
TRUJILLO494 SAND WITH GRAVEL 20.60 19.93 17.43 20.60 0.021
9 CIP CIP CAJAMARCACAJAMARCA,
CAJAMARCA, CAJAMARCA393 CLAYEY GRAVEL 17.27 17.63 9.44 17.63 0.018
10 CIP / UPAO UPAOLA LIBERTAD, TRUJILLO,
TRUJILLO495 CLAYEY SAND 16.71 17.62 13.63 17.62 0.018
11 CIP CIP PIURA PIURA, PIURA, PIURA 596 CLAYEY SAND 17.23 15.54 10.68 17.23 0.017
12 CIP CIP TUMBESTUMBES, TUMBES,
TUMBES619
LOW COMPRESSIBILTY
CLAY14.59 11.48 5.93 14.59 0.015
13 CIPCIP
LAMBAYEQUELAMBAYEQUE, CHICLAYO,
PIMENTEL528 CLAY WITH SILT 13.17 13.41 13.61 13.41 0.013
Methodological summary and results
• This earthquake was registered in more than 60 accelerographic stations in Peru
and Ecuador.
• The maximum acceleration recorded in Peru was at the UNTRM Station in
Chachapoyas, an EO component of 95.84 cm/sec². The maximum acceleration
recorded in Ecuador was at the Barrio Centenario Station in Guayaquil, EO
component of 36.70 cm/sec².
• The records were corrected by baseline and filtered (band-pass from 0.1 hertz to
25 hertz) before proceeding to identify the maximum acceleration peaks, with the
use of SIPA v. 2017.
Effects on society and nature: Losses and damages
• 2 people dead, and 32 injured (17 in Peru, 15 in
Ecuador).
• 1,633 affected houses, 716 of which declared
inhabitable.
• 296 schools affected, 7 inhabitable.
• 40 health centers, 6 inhabitable.
• 15 religious buildings, 5 collapsed.
• 21 commercial buildings.
• 54 km of affected highway roads.
• 5 pedestrian bridges affected, 1 collapsed.
National Emergency Operations Center (COEN), 30 May 2019 .
Yurimaguas (Province of Alto Amazonas, Loreto)
60 km from the epicenter.
Santa Cruz Church (Province of Alto Amazonas, Loreto). 40 km.
Progreso School (Distrito de Santa Cruz, Province of Alto Amazonas, Loreto)
Huatapi Health Centre (Distrito de Santa Cruz, province of Alto Amazonas, Loreto)
Cajamarca – Cajabamba
Highway (340 km from the
epicenter)
Tarapoto – Yurimaguas
Highway (80 km from the
epicenter)
Affected highways
Seis de Enero Town centre
(Distrito de Santa Cruz, Alto
Amazonas, Loreto)
Ground effects
Seis de Enero Town centre (Santa Cruz, Alto Amazonas, Loreto)“El Sauce” Resort (San Martín)
Malecón del río Huallaga (District of Lagunas,
Province of Alto Amazonas, Loreto)
Centro Poblado Tamarate, near the district
of Lagunas (Rengifo, 2019).
MAP OF MAXIMUM CREDIBLE EARTHQUAKE ( 500 year of return period)
S2
NORMALIZED RESPONSE SPECTRA FROM DATA MAY 26, LAGUNAS EARTHQUAKE
Period (s)
Seis
mic
Am
plif
icat
ion
From PERUVIAN CODE E.030 (2018)
Site coefficient “S”
Short Period (Tp) and Long Period (TL)
GEOPHYSICAL TESTS CARRIED OUT (MICROTREMORES, MASW, MAM Y RESISTIVIDAD ELECTRICA) IN
JAEN, CHACHAPOYAS, MOYOBAMBA AND TARAPOTO
SEISMIC STATION UNTRM
Time (s)
PSEUDO ACCELERATION RESPONSE SPECTRUM – UNTRM STATION
M8.0 Lagunas, Peru Earthquake. May 26, 2019
FOURIER AMPLITUDE SPECTRUM – UNTRM STATION
M8.0 Lagunas, Peru Earthquake. May 26, 2019
Acc
ele
rati
on
(cm
/s2)
Acc
ele
rati
on
(cm
/s2)
Acc
ele
rati
on
(cm
/s2)
Time ( sec)
Time ( sec)
Time ( sec)
Period ( s )
Pse
ud
o-A
cce
lera
tio
n(c
m/s
2)
Am
plit
ud
e(c
m/s
2-s
)
Frequency (Hz)
Vs30 = 241 m/s SUELO TIPO DS2
UNTRM STATION
0.0
3.0
6.0
9.0
12.0
15.0
18.0
21.0
24.0
27.0
30.0
0 100 200 300 400 500 600 700
Pro
fun
did
ad [m
]Vs [m/s]
1
2
3
SPECTRAL RATIO H/V– ACCELEROGRAPH
Period ( s )
Am
plit
ud
e(H
/V)
Period ( s )A
mp
litu
de
(H/V
)
SPECTRAL RATIO H/V– MICROTREMOR
DEP
TH (
m)
S-WAVE VELOCITY PROFILE
FROM : MASW RESULTS
UNTRM STATION
20.0
18.0
16.0
14.0
12.0
10.0
8.0
6.0
4.0
2.0
-0.0
-2.0
Depth
(m
)
0.0 4.0 8.0 12.0 16.0 20.0 24.0 28.0 32.0 36.0 40.0 44.0 48.0
Distance (m)
Vs- UNTRM
(m/sec)
Vs
150
200
250
300
Scale = 1/200
0
10
20
30
40
50
60
70
80
90
100
0 200 400 600 800 1000
Pro
fundid
ad [
m]
Vs [m/s]
1
2
3
Estrato Vs(m/s)
1 <150
2 150-200
3 200-250
4 250-300
Caracterización geotécnica
Material de consistencia muy blanda
Material de consistencia blanda
Material de consistencia media
Material de consistencia dura
20.0
18.0
16.0
14.0
12.0
10.0
8.0
6.0
4.0
2.0
-0.0
-2.0
Depth
(m
)
0.0 4.0 8.0 12.0 16.0 20.0 24.0 28.0 32.0 36.0 40.0 44.0 48.0
Distance (m)
Vs- UNTRM
(m/sec)
Vs
150
200
250
300
Scale = 1/200
Vs100 = 370 m/s
DEP
TH (
m)
FROM : MASW AND MAM RESULTS
FROM : MASW-2D RESULTS
S-WAVE VELOCITY PROFILE
CIP TARAPOTO STATION
20.0
18.0
16.0
14.0
12.0
10.0
8.0
6.0
4.0
2.0
-0.0
Depth
(m
)
0.0 4.0 8.0 12.0 16.0 20.0 24.0 28.0 32.0 36.0 40.0 44.0 48.0
Distance (m)
Vs-CIP TARAPOTO
(km/sec)
Vs
0.20
0.25
0.30
0.35
0.40
0.45
Scale = 1/250
Estrato Vs(m/s)
1 200-250
2 250-300
3 300-350
4 350-400
Material de consistencia dura
Material de consistencia rígida
Caracterización geotécnica
Material de consistencia blanda
Material de consistencia media a dura
Vs80 = 381 m/s
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
0 100 200 300 400 500 600
Pro
fundid
ad [
m]
Vs [m/s]
2
1
3
4
FROM : MASW AND MAM RESULTS
FROM : MASW-2D RESULTS
S-WAVE VELOCITY PROFILE
DEP
TH (
m)
• In Peru, the periods of the study area were determined by two different methods:
spectral quotient of the microtremors records, spectral quotient of the time-history
records of acceleration, concluding that the values of soil periods increase with
earthquakes of greater magnitude with respect to the values obtained by
microtremors measurements due to the effect of the non-linearity of the soil.
• The shear-wave velocity profiles (Vs) were determined in the accelerographic
booths of Peru, at different depths those that classified according to Standard E-
030 as intermediate soil (S2) and according to ASCE-7 Type D and C soils.
Methodological summary and results
• The Andean Amazonian belt: area of intermediate-depth high-magnitude earthquakes.
They have large perception areas.
• The strength is attenuated by focal depth (100 – 150 km) and the thick sedimentary
pack they traverse. Moderate intensities (< V MM) were expected. Nonetheless, some
areas may be strongly affected. Process of disaster risk management is a priority.
• Intense damage and losses are related to regional to:
a) Flat to gently inclined river terraces, subjected to periodic fluvial and pluvial floods.
b) Bad quality foundation soils: developed on transported loose sand-silt-clay mixes
with shallow groundwater table.
c) Precarious settlement without guidelines for risk management,
d) Absence of actions for risk reduction and preparedness face to natural hazards.
Recommendation: General and thorough assessment of risk, planning safe land
occupation, actions for risk reduction, and capacity strengthening to local authorities for a
safer, healthier and sustainable development.
Conclusive remarks and recommendation for DRM