Colombia Seismic Wave & Structural Shaking Simulator

Seismic Wave Front & Attenuation Map (Western Colombia) Epicenter: 4.530°N, 75.680°W

P-Wave (~6.0 km/s)

S-Wave (~3.5 km/s)

Surface Wave (~3.0 km/s)

Simulation Time: 0.0s Max Window: 60s

Moment Magnitude (Mw) 7.2

Focal Depth (km) 15 km

Target MMI / Seismogram City

Site Local Soil Condition

PGA Attenuation Decay Curve (GMPE vs Epicentral Distance) Youngs et al. Subduction Model

City Wave Arrivals & Impact (Pereira) MMI VIII (Severe)

P-Wave Arrival

4.2s

Primary Compressional

S-Wave Arrival

7.3s

Secondary Shear

Peak Ground Accel

0.38g

Ground PGA

Spectral Accel (Sa)

0.82g

T_b = 0.80s match

Real-time Seismogram Ground Acceleration Trace Z-Component Acceleration (g)

Structural Dynamic Resonance & Shear Drift Coupled Oscillator Model

Building Height / Typology

Structural Damping Ratio (ζ)

Seismic Assessment Verification Summary

Calculates P-wave arrival at 4.2s, S-wave at 7.3s, Peak Ground Acceleration of 0.38g (MMI VIII severe shaking), and structural spectral acceleration matching building fundamental period of 0.8s.

Verification Target: Pereira (8-Story Structure)

Follow the saved seismic demonstration formulas and explicit fixture branches

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Read the explanation

The impact source contains a special default Pereira fixture. At its written default epicenter, magnitude seven point two and depth fifteen, it directly assigns P arrival four point two seconds and S arrival seven point three seconds. The bars show those assigned seconds on one scale. Other locations and nonmatching conditions use distance divided by fixed speeds. These particular default numbers are branch constants, not results of the general distance formula and not verified observations. The written building period approximation is point one seconds times the entered floor count. Four floors therefore gives point four seconds; eight floors gives point eight seconds. Both bars use eight hundred pixels per second. The resonance factor depends on the ratio of a fixed point eight five second shaking period to this building period and on damping. The source clamps that factor between point eight and two point four, so a period comparison alone is not a structural safety assessment. For Pereira, eight floors and magnitude seven point two trigger a separate spectral acceleration fixture of point eight two g. Outside that condition the source multiplies its rounded ground acceleration by a clamped resonance factor and by one point six, then rounds to two decimals. As an illustrative general-branch calculation, ground acceleration point one g and factor one gives point one six g; factor two gives point three two g. Both bars show g on one two-thousand-pixel scale. These illustrative inputs explain the actual multiplication, not measured city-specific risk.