Seismic Activity Observation — July 6, 2025(Tokara Region Cluster & Global Swarm Status)

✅ 2️⃣ Core Summary

• Focus Zone: Tokara Islands, Ryukyu Trench, Hyuganada, Eastern Honshu
• Key Events:
  • Two M5.5 shocks detected in Tokara region
  • Continuous micro-swarm (M2.5–M3.5) every 10–30 minutes
  • Parallel swarm activity: Indonesia, Nicobar Islands, Alaska, Central Asia, Turkey

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✅ 3️⃣ Observed Data

• Observation Window: July 5, 21:00 ~ July 6, 20:00 JST
• Peak Magnitude: M5.5 (twice)
• Residual Activity: Persistent micro-swarms — no full quiet zone yet
• Energy Pattern: Total seismic energy (log scale) is still increasing
• Main Behavior: Slow slip + chain slip + swarm pattern → Partial core rupture → Residual stress remains visible

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✅ 4️⃣ Analysis

Key Points:
1️⃣ Double M5.5 = Partial Core Break, Not Total Release

• The back-to-back M5.5 indicates core tension was only partially released.
• Small quakes continuing at short intervals means residual fault slip is ongoing.

2️⃣ Cumulative Energy = Still Rising

• The energy curve has not flattened — indicates sustained stress transfer.
• If the curve flattens, the swarm is dissipating naturally.

3️⃣ Current Phase = Temporary Lull

• Present status: not resolved — a pause while slow slip disperses stress.
• If swarm frequency drops to zero → Full relief.
• If swarm frequency stays or scales up → M4–5 re-trigger likely.

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✅ 5️⃣ Next 24h Outlook

• If micro-swarms persist → 40–60% probability of new M4–5 event within 12–24h.
• If swarm frequency sharply declines → natural resolution dominant.
• High-priority watch line: Tokara → Ryukyu → Hyuganada → Nankai Trough boundary.

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✅ 6️⃣ Monitoring Focus

• Keep tracking: swarm interval, small-magnitude density.
• Critical sign: any sudden jump to M4+ indicates possible swarm reactivation.
• Update cumulative energy + swarm frequency graphs every 6–12h.