Earthquake Nucleation Hypotheses

Deterministic Hypothesis: Gradual aseismic pre-slip in a nucleation zone accelerates until reaching a critical size, triggering the mainshock. Foreshocks are passive markers of the ongoing preparation process.

Time Control

Simulation Time: 0.0 s

Start Nucleation Mainshock

Fault Segment Evolution

Loading Phase

Stress Level

Nucleation Zone

Passive Foreshocks

Active Triggers

Simulation Parameters

Fault Properties

Fault Length 50 km

Background Stress 0.8

Stress Heterogeneity 0.3

Deterministic Parameters

Pre-slip Rate 1.0

Critical Zone Size 8.0 km

Nucleation Duration 30 s

Cascade Parameters

Initial Event Rate 0.5

Triggering Efficiency 0.7

Stress Transfer Decay 3.0 km

Visualization

Animation Speed 1.0x

Stress Sensitivity 2.0

Understanding Earthquake Nucleation Mechanisms

🎛️ Time Slider Control: Use the time slider to manually control the progression of the earthquake nucleation process. This allows you to observe the critical differences in timing and spatial patterns between the two hypotheses.

🎯 Deterministic Process

Gradual Preparation: Watch the nucleation zone (blue outline) grow slowly and steadily
Accelerating Pre-slip: Slip rate increases exponentially as critical size approaches
Passive Foreshocks: Yellow dots appear as byproducts, not triggers
Critical Threshold: Mainshock occurs when zone reaches critical size
Predictable Timing: Process follows deterministic laws

🎲 Cascade Process

Stochastic Initiation: Starts with random small foreshock event
Active Triggering: Each event transfers stress to neighbors (purple lines)
Emergent Patterns: Larger events emerge from smaller ones unpredictably
Cascading Growth: Chain reaction of increasingly larger events
Unpredictable Timing: Mainshock timing depends on random cascade

🔬 Key Observables:

Spatial Patterns: Deterministic shows localized preparation zone; Cascade shows distributed activity
Temporal Evolution: Deterministic has smooth acceleration; Cascade has irregular bursts
Foreshock Role: Passive indicators vs active triggers
Predictability: Deterministic process could enable forecasting; Cascade is inherently random

🎮 Interactive Features: Use the time slider to step through the process at your own pace. Switch between hypotheses to compare their signatures. Adjust parameters to explore how fault conditions influence nucleation behavior.