… · … · Reviewed
Río Grande西 22 km
Veraguas，巴拿马
How long it took to reach you
Turn on your location to time the wave.
Why it shakes here
8 km deep. Without your location we do not estimate how it felt where you are.
震级
- < 3
- 3–4.9
- 5–5.9
- 6+
距离
—
Shaking
—
Turn on your location to time the wave.
深度
8 km
shallow
Aftershocks in this sequence
0
30 km · 2 d
Lat / Lon
7.701, -81.537
UTC 00:16:14
Estimate
How it reached you
Turn on GPS or save a zone to estimate arrival and intensity where you are. The epicenter can still be estimated.
Wave arrival
The P wave arrives first and is faster. The S wave comes later and is usually what you feel. Time is hypocentral distance divided by a constant crustal speed: Vp ≈ 6.0 km/s and Vs ≈ 3.5 km/s. This is not a 3D travel time.
Turn on GPS or save a zone to estimate arrival and intensity where you are. The epicenter can still be estimated.
Intensity where you are
At the epicenter
IV
Estimate · MMI 4.4
Many people indoors feel it. Dishes and windows move.
Turn on GPS or save a zone to estimate arrival and intensity where you are. The epicenter can still be estimated.
The Mercalli scale runs to XII. This page shows I–X, the range of the equation.
What the magnitude means
Published magnitude: 4.5 M.
This is moment magnitude (Mw). It measures rupture size: area, slip and rigidity. It does not say how it felt at a place.
Magnitude is one number for the earthquake. Mercalli intensity changes with place: the same event is strong nearby and weak far away. Richter is not Mercalli.
Estimated radiated energy: 3.5×10^11 J. From log10(E) = 1.5 Mw + 4.8, with E in joules. One more Mw unit multiplies that energy by 31.6.
I live in a building
Floor and era are saved in this browser, under Settings.
What to do at that level
House
Dishes and doors may move. If it grows, drop, cover and hold on. Stay away from windows.
Technical detail
Atkinson & Wald (2007) intensity prediction equation, California coefficients (Table 1). D is the catalog hypocentral distance and R = √(D² + 14²). The paper’s residual is about 0.4 MMI units. It was calibrated on California reports, not Panama. Atkinson, Worden & Wald (2014) note that it can overpredict large magnitudes at short range.
Equivalent motion
PGA ≈ 41.8 cm/s² (0.043 g)
PGV ≈ 2.6 cm/s
This is not a recording of this earthquake. It is the PGA and PGV that Worden et al. (2012) associate, at the median, with that intensity, without the optional magnitude and distance residual. Scatter is about 0.35 in log10(PGA) and 0.38 in log10(PGV).
Shearer, P. M. (2009). Introduction to Seismology. Vp = 6,0 km/s y Vs = 3,5 km/s como velocidades constantes de corteza. Estimación, no un tiempo de viaje 3D.
Atkinson, G. M., & Wald, D. J. (2007). “Did You Feel It?” intensity and ground-motion intensity conversion equations. Seismological Research Letters, 78(3), 362–368. doi:10.1785/gssrl.78.3.362. Coeficientes de California, tabla 1.
Atkinson, G. M., Worden, C. B., & Wald, D. J. (2014). Intensity prediction equations for North America. Bulletin of the Seismological Society of America, 104(6), 3084–3093. doi:10.1785/0120140178. AW07 puede sobrestimar magnitudes grandes a poca distancia.
Worden, C. B., Gerstenberger, M. C., Rhoades, D. A., & Wald, D. J. (2012). Probabilistic relationships between ground-motion parameters and modified Mercalli intensity in California. Bulletin of the Seismological Society of America, 102(1), 204–221. doi:10.1785/0120110156. Inversión de la mediana bilineal (ShakeMap wgrw12).
Kanamori, H. (1977). The energy release in great earthquakes. Journal of Geophysical Research, 82(20), 2981–2987. Hanks, T. C., & Kanamori, H. (1979). A moment magnitude scale. Journal of Geophysical Research, 84(B5), 2348–2350. log10(E en julios) = 1,5 Mw + 4,8.
Periodo del edificio ≈ 0,1 × N segundos. Regla práctica del orden de las fórmulas de periodo de marcos (Chopra; ASCE 7). No es un análisis estructural.
Brune, J. N. (1970). Tectonic stress and the spectra of seismic shear waves from earthquakes. Journal of Geophysical Research, 75(26), 4997–5009. fc = 4,9×10^6 × β × (Δσ/M0)^(1/3), con β = 3,5 km/s, Δσ = 30 bar (3 MPa) y M0 en dyn·cm. La caída de esfuerzos es un orden de magnitud de corteza (Kanamori & Anderson, 1975), no una medición de este sismo.
Escala de intensidad de Mercalli modificada, descriptores en la línea de la ficha pública del USGS. La escala llega a XII; esta ecuación se muestra entre I y X.
Did you feel it?
Community reports are off. When they are on, this card opens the same form.
What should I do now?
What happened
Magnitude 4.5 earthquake, Río Grande西 22 km (Veraguas，巴拿马), 8 km deep. It happened 前天 (…).
Turn on your location to see how it may have felt where you are.
What to do
- 1If it is still shaking: drop, cover and hold on.
- 2Check everyone is okay and put on shoes.
- 3Small aftershocks may follow. That's normal.
- 4Text your family instead of calling.
Aftershocks: they may occur over the next 2 days within about 30 km. Nobody can predict them.
Emergency numbers in 巴拿马
Call emergency services only for a life-threatening emergency or trapped people. To tell your family, send a message.
From a mobile phone, 112 works in many countries even without credit.
The main quake and its aftershocks
We count as an aftershock anything within 2 days and 30 km. We do not forecast aftershocks. If USGS publishes one, we link it.
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Comments0
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Aftershocks in this sequence
0No aftershocks recorded yet. If any appear, they show up here right away.
Other quakes in the area
0No earthquakes recorded in this area in the last 7 days.