The Earth’s oceans cover over 70% of the planet, and their movement has a profound impact on the environment. One aspect of ocean movement that has gained significant attention in recent years is the tiny wave vibrations that occur in the Gulf of Alaska. These vibrations, which are too subtle for humans to notice, can travel through land and provide valuable insights into climate change.
The research, conducted by doctoral student Sebin John at the University of Alaska Fairbanks Geophysical Institute, reveals a correlation between ocean waves and seismic signals recorded in the ground in Alaska. The signals, known as microseisms, are also strongly affected by sea ice.
“Microseisms provide a long-term record of meteorological, seasonal and climate influences,” said Sebin John, a doctoral student at the University of Alaska Fairbanks Geophysical Institute. “There is a revival of a field called the environment of seismology, which is using seismology to learn about climate change.”
Microseisms are continual background noise for seismologists focusing on earthquake data, but they offer a unique opportunity for researchers to study climate change. By analyzing microseismic activity, scientists can gain insights into:
* Meteorological trends, such as storm intensity and trajectory
* Seasonal and climate influences on the environment
* The dynamics of sea ice and its impact on the climate
The data collected from microseisms can be used to track the evolution of phenomena driven by climate, such as ocean storms and sea ice. However, seismic noise is one of the few methods that has captured second-by-second changes around the globe continuously over decades.
- Types of microseisms:
- Primary microseisms:
- Secondary microseisms:
- Short-period secondary microseisms:
Microseisms come in three types of signals, each tied to a different oceanic process. Secondary microseisms are the strongest of the three and arise from the interaction of opposing wave systems in deeper water. These waves, called standing waves, oscillate vertically in place and transmit energy through the Earth as secondary microseisms.
Key Findings:
* The Gulf of Alaska is the primary source of far-reaching secondary microseisms, which were recorded by sensors in each of the six designated regions. * Sea ice suppresses short-period secondary signals. * The amount of energy from a standing wave varies by storm, creating several decibels of additional power for each few feet of wave height.
| Region | Far-Reaching Secondary Microseisms | Short-Period Secondary Signals |
|---|---|---|
| Aleutian Islands | Yes | No |
| Bering Sea | Yes | No |
| Gulf of Alaska | Yes | No |
| Chukchi Sea | Yes | No |
| Beaufort Sea | Yes | No |
| Arctic Ocean | Yes | No |
Sebin John’s research demonstrates the importance of using seismology to study climate change. The Arctic region is particularly crucial in understanding environmental change, and the findings of this study provide valuable insights into the impact of ocean waves and sea ice on the climate.
Conclusion:
The study’s results highlight the potential of microseisms as a tool for researching current and past climate trends. By analyzing the data collected from microseisms, scientists can gain a better understanding of the complex relationships between ocean waves, sea ice, and climate change.
