Successful Earthquake Forecast Cases (Taiwan & Vanuatu) 2023 – Tectonic Waves

The Earth's dynamic nature unfolds through a constant interplay of geological processes, with seismic activity and tectonic waves serving as fundamental elements in this process. Tectonic waves are an important part of Quantectum’s earthquake forecasting because by monitoring and studying their characteristics, we can gain insights into the ongoing tectonic activity in an area, which helps in identifying regions that are more prone to earthquakes. Additionally, by monitoring tectonic waves, we can detect foreshocks and aftershocks, providing important clues about the likelihood of a larger earthquake occurring in the vicinity.

This blog post dives deep into the importance of tectonic waves in the process of earthquake forecasting, highlighting two seismic cases: the M5.9 Taiwan earthquake on the 23^rd of October 2023 and the M6.0 Vanuatu earthquake on the 29^th of October 2023.

The impact of tectonic waves is illustrated in the chronological account of the earthquakes they have triggered in the list below, which provides information on the earthquake occurrence by the global tectonic wave in October 2023:

- 2023-10-21 M4.8 Admiralty Islands Region,
- 2023-10-22 M6.5 south of Fiji islands,
- 2023-10-22 M5.0 near the coast of Fujian, China,
- 2023-10-22 M5.1 Gansu, China,
- 2023-10-22 M4.3 off the coast of northern Peru,
- 2023-10-22 M4.0 Philippine islands region,
- 2023-10-23 M4.6 Taiwan region,
- 2023-10-23 M5.9 Taiwan region,
- 2023-10-23 M4.8 south of Fiji islands,
- 2023-10-23 M5.6 eastern New Guinea region, P.N.G.,
- 2023-10-23 M4.6 eastern New Guinea region, P.N.G.,
- 2023-10-24 M5.5 Gansu, China,
- 2023-10-24 M4.7 south of Fiji islands,
- 2023-10-24 M4.0 southern Xinjiang, China,
- 2023-10-24 M4.1 south of Fiji islands,
- 2023-10-25 M4.1 Gansu, China,
- 2023-10-25 M4.0 Peru-Ecuador border region,
- 2023-10-25 M4.9 eastern New Guinea region, P.N.G.,
- 2023-10-25 M4.0 Peru-Ecuador border region,
- 2023-10-26 M5.1 Philippine islands region,
- 2023-10-27 M4.0 near the coast of northern Peru,
- 2023-10-27 M4.2 near the coast of northern Peru,
- 2023-10-28 M4.8 eastern New Guinea region, P.N.G.,
- 2023-10-28 M4.3 Taiwan region,
- 2023-10-29 M6.0 Vanuatu,
- 2023-10-24 M4.1 south of Fiji islands,
- 2023-10-29 M4.0 Taiwan.

Picture 1: Tectonic waves triggering a series of notably strong earthquakes across the globe in October 2023.

Quantectum’s Issued Earthquake Alerts

In response to the heightened seismic activity triggered by the global tectonic wave marked in Picture 1, Quantectum issued earthquake alerts in regions vulnerable to its influence. These alerts are the result of a comprehensive analysis that takes into account various factors influencing earthquake occurrence and intensity. Two of the key elements considered are tectonic tractions and fault instability, as they often serve as a precursor to significant seismic events.

Quantectum’s Operations Center operators issued a yellow earthquake alert (2/4) in the weekly earthquake forecast for areas of Papua, Luzon, the Philippines, and Northern Peru, indicating an elevated risk of seismic activity. Furthermore, they issued the orange alert (3/4) for regions of Vanuatu and Taiwan, indicating a higher probability of a significant earthquake event.

Picture 2: Issued yellow and orange alerts in the region.

In the wake of the issued orange alert, which signaled an elevated risk of significant seismic activity in Taiwan and Vanuatu, two notably stronger earthquake events indeed occurred:

1) On the 23^rd of October 2023, the Taiwan region experienced an earthquake with a magnitude of 5.9 on the Richter scale. While a magnitude of 5.9 may not be considered extremely powerful, it can still cause significant damage to infrastructure and pose risks to the safety of the population, especially if buildings and infrastructure are not adequately designed or retrofitted to withstand such events.

2) Just a few days later, on the 29^th of October 2023, Vanuatu experienced an even stronger earthquake with a magnitude of 6.0.

Picture 3: M5.9 Taiwan and M6.0 Vanuatu earthquakes marked on the same seismic waves that are triggering a series of notably strong earthquakes across the globe.

M5.9 Taiwan Region Earthquake (23^rd of October 2023)

On the 23^rd of October 2023, at 23:05:25 UTC, a stronger seismic event occurred in the Taiwan region. The earthquake was recorded at a magnitude of 5.9 and took place at a depth of 35 km (27,7 mi), with its epicenter located at 24.06° latitude and 122.65° longitude, according to the USGS.

Picture 4: Epicenter of the M5.9 earthquake in the Taiwan region on the 23^rd of October 2023, marked by concentric circles.

The seismic activity in this particular region can be attributed to the influence of an elevated shear traction field generated by nearby tectonic waves, as shown in Picture 6. Shear traction plays an important role in the buildup of stress along fault lines, ultimately leading to the release of energy in the form of earthquakes. When this shear traction field is intensified by the movements of tectonic plates in proximity, it creates the conditions ripe for seismic events.

The presence of widespread tectonic instability in the region serves as a reminder of the intricate geological processes occurring beneath the Earth's surface. Tectonic waves, driven by the movement and interaction of Earth's plates, result in a dynamic and ever-changing landscape of tectonic stress and strain. These forces, accumulating over extended periods, can suddenly be released, setting off a chain reaction of seismic events.

Picture 5: Elevated shear traction, seismic waves, and critical regions (black pixels) combined triggered the M5.9 earthquake in the Taiwan region.

Quantectum’s Operations Center carefully monitors and keeps track of the changes in seismic activity along the corresponding tectonic waves. The map below illustrates the increased strength of the dynamic traction field in the proximity of the seismic event, corresponding to the elevated scores along the tectonic waves. This implies that areas experiencing intense earthquakes also exhibit numerous smaller earthquakes along the same tectonic lines. The score describes the number of the occurred seismic events along the relevant tectonic waves.

Picture 6: High dynamic traction field (red) in the surroundings of the M5.9 earthquake in the Taiwan region.

Furthermore, the critical potential, a key factor in evaluating seismic risk, pointed to an increased probability of significant seismic events in the Taiwan region. Utilizing Ultra-High-Definition (UHD) models, the region was in an elevated phase of critical potential, further underlining the risk factor associated with this earthquake, as shown in the picture below.

Picture 7: The critical potential shows a very high probability (purple curve) for earthquake triggering at the time of the M5.9 earthquake in the Taiwan region (represented by a black column).

In terms of impact, Quantectum's macroseismic intensity map indicated that this earthquake reached an intensity level of "V", suggesting moderate shaking and the potential for no or slight damage. It implies that residents in the affected region would have likely felt the ground shaking, but structural damage to well-constructed buildings should be minimal. However, there may be a risk of minor damage to less sturdy structures, such as old or unreinforced buildings, and some disruptions to utilities and transportation infrastructure cannot be ruled out.

Picture 8: Macroseismic intensity map and exposed cities, towns, and villages with a population above 500 (colored hexagons) for the M5.9 earthquake in the Taiwan region.

In summary, the Taiwan Region earthquake of October 23, 2023, was a notable seismic event characterized by its magnitude, depth, and geological influences. Quantectum's alert system proved valuable in providing timely warnings for those in the affected region.

M6.0 Vanuatu Earthquake (29^th of October 2023)

On the 29^th of October 2023, at 04:32:01 UTC Vanuatu, located at -19.41° latitude and 168.84° longitude, experienced a significant seismic event. This earthquake registered a magnitude of M6.0 and occurred at a depth of 80 km (49,7 mi), as reported by EMSC (https://www.emsc-csem.org/).

Picture 9: Epicenter of the M6.0 Vanuatu earthquake (illustrated by concentric circles) that occurred on the 29^th of October 2023.

The impact of this seismic event was profound, with Quantectum's ShakeMap classifying the maximum intensity as “VI”, signifying a strong shaking intensity. Despite this intensity, the damage assessment suggested only a slight level of damage, highlighting the resilience of the region's infrastructure.

Picture 10: The estimated model of macroseismic intensity in the area during the M6.0 earthquake in Vanuatu (29^th of October 2023).

Local time-synchronizations played a pivotal role in setting the stage for this seismic event, making the region unstable. Quantectum's models further illustrated the mean expected magnitude in the area, providing insights into the expected seismic activity. On the map below, it is well-visible that the earthquake occurred on the part of the Vanuatu region where the largest magnitudes could be expected due to the strong chaotic synchronizations along the regional fault system.

Picture 11: Mean expected magnitude M0 according to the UHD time-synchronization model.

The tectonic instability around the epicentral region was also indicated by the increased earthquake-triggering potential. This parameter describes the joint influence of the tectonic tractions and fault instability and gives an estimation of earthquakes’ occurrence.

Picture 12: Local interaction potential illustrating the local instabilities of tectonic zones according to the UHD Time-synchronization model.

This region was indeed under the influence of both global and regional tectonic waves, making it a hotspot for seismic activity, with the forecasted potential shear traction field indicating a notably high level in the direct surroundings of the epicenter. These factors contributed to the increased risk of seismic activity in the area.

Picture 13: Forecasted shear traction field in the region according to the global HD model.

Conclusion

Quantectum's commitment to monitoring seismic events and the implementation of an alert system, ensure that communities and authorities are well-prepared to adequately address potential seismic challenges. Our timely alerts serve as a reminder of the importance of earthquake preparedness in seismically active regions.

The M5.9 Taiwan region earthquake on the 23^rd of October 2023, and the M6.0 Vanuatu earthquake on the 29^th of October 2023, show the importance of earthquake forecasting. Understanding the complexities of seismic events and being prepared for potential risks is fundamental to safeguarding communities and their well-being. Quantectum's commitment to this endeavor ensures that we are better equipped to navigate the ever-evolving narrative of our dynamic planet.