Seismic Surveillance and Seismo-Tilt Monitoring on Hualalai and Haleakala Volcanoes in Hawaii

Hawaii, renowned for its beautiful landscapes and active volcanoes, has a continuous monitoring system in place. This system is designed to track seismic activity, which can provide early warnings of potential volcanic eruptions. One may wonder, given the seismic history of Hualalai and Haleakala, why tilt meters are not installed as a part of this surveillance system. This article delves into the current monitoring practices and the rationale behind the decision to not place tilt meters on these volcanoes.

Hualalai and Haleakala Monitoring Systems

Hualalai, the third-most active volcano on the Hawaiian Islands, last erupted in 1801. However, in 1929, a cluster of earthquakes occurred beneath the mountain, leading to significant seismic activity. According to the United States Geological Survey (USGS), Hualalai is currently monitored through a network of advanced scientific instruments. A continuously recording GPS receiver is placed on the summit of Hualalai. Additional seismometers are positioned southeast of the summit and on the flanks of Mauna Kea and Mauna Loa. These instruments not only detect seismic events but also help in assessing any ground deformation that might indicate an impending eruption.

Haleakala is the other major volcano in question. Similar to Hualalai, Haleakala is also closely monitored by the USGS. The primary monitoring equipment includes a continuous GPS instrument and a seismometer located near the southwest edge of the crater. Periodic resurveying of key sites using GPS receivers allows for the detection of any changes in the volcano's shape. The most recent lava flow at Haleakala dates back to approximately 870 years ago. Geological models suggest that Haleakala is likely to resume volcanic activity within the next 500 years.

The Rationale for Not Installing Tilt Meters

Given the history of the volcanoes, one might question why tilt meters, which are essential for detecting ground deformation and monitoring the growth of active volcanoes, are not installed on Hualalai and Haleakala. Tilt meters are indeed valuable tools in volcanic monitoring, as they can provide precise measurements of ground deformation over time. However, the decision to not install these instruments is based on a combination of factors, including the current monitoring capabilities and the likelihood of immediate seismic activity.

The U.S. Geological Survey (USGS) has established a robust system of instruments that can detect seismic activity originating from both Hualalai and Haleakala. Seismic swarms, like the one in 1929, can be effectively monitored through these instruments, providing an advance warning system. If seismic activity increases, the USGS can quickly deploy more precise instruments, such as tilt meters, to provide detailed data. Such an approach is cost-effective and ensures that the limited resources are utilized efficiently.

Similarly, Haleakala, being less active than Hualalai, also relies on the existing monitoring networks. The regular resurveying using GPS receivers is sufficient to detect any significant changes in the volcano's shape. While tilt meters would certainly provide additional detail, the current system can still detect significant ground deformation without them.

Conclusion

In conclusion, the current monitoring systems on Hualalai and Haleakala are designed to provide detailed information about seismic and volcanic activity. While tilt meters are highly useful tools, their installation is currently unnecessary due to the existing technology and the potential for rapid deployment. The USGS continues to refine these systems, ensuring that the Hawaiian Islands remain safe and well-monitored.

Frequently Asked Questions (FAQs)

Why are tilt meters not installed on Hualalai and Haleakala?
Tilt meters are not installed immediately because the current monitoring systems can detect seismic activity effectively. These instruments are deployed when necessary to provide more precise data. What is the frequency of seismic activity monitored on Hualalai and Haleakala?
Hualalai experienced a seismic swarm in 1929 but has remained relatively dormant since 1801. Haleakala's most recent lava flow was around 870 years ago and is expected to resume activity within the next 500 years. How does GPS contribute to volcanic monitoring?
GPS instruments are used to detect significant changes in the shape of the volcano, which can indicate potential volcanic activity. Regular resurveys using GPS receivers help in monitoring these changes.

For those interested in learning more about volcanic monitoring and the specific technologies used, the U.S. Geological Survey's website is an excellent resource. Keep up with the latest updates on volcanic activity in Hawaii to ensure safety and awareness.