Solar storms and submarine internet cables (2211.07850v2)

Abstract: Coronal mass ejections (CMEs) can trigger geomagnetic storms and induce geoelectric currents that degrade the performance of terrestrial power grid operations; in particular, CMEs are known for causing large-scale outages in electrical grids. Submarine internet cables are powered through copper conductors spanning thousands of kilometers and are vulnerable to damage from CMEs, raising the possibility of a large-scale and long-lived internet outage. To better understand the magnitude of these risks, we monitor voltage changes in the cable power supply of four different transoceanic cables during time periods of high solar activity. We find a strong correlation between the strength of the high-frequency geomagnetic field at the landing sites of the systems and the line voltage change. We also uncover that these two quantities exhibit a near-linear power law scaling behavior that allows us to estimate the effects of once-in-a-century CME events. Our findings reveal that long-haul submarine cables, regardless of their length and orientation, will not be damaged during a solar superstorm, even one as large as the 1859 Carrington event.

• The paper demonstrates a near-linear power law relationship, showing that submarine cables withstand severe CMEs without catastrophic damage.
• Robust continuous voltage monitoring and magnetometer analysis revealed a high correlation (0.97) between geomagnetic disturbances and cable voltage changes.
• Findings imply that modern cable designs, with dual power feeds and regulation strategies, significantly mitigate risks from solar superstorms.

Solar Storms and Their Impact on Submarine Internet Cables

This paper by Jorge C. Castellanos et al. examines the vulnerability of submarine internet cables to Coronal Mass Ejections (CMEs), with a particular focus on large-scale solar superstorms. The research is set in the context of past significant geomagnetic events, such as the Carrington Event of 1859 and its potential ramifications on modern infrastructure. The paper's objective is to understand the consequences of CMEs on these deep-sea communication links, which are critical to the global internet infrastructure.

Key Findings and Methodology

The authors monitored voltage fluctuations in the power supply of four transoceanic submarine cables during periods of high solar activity. They focused on the correlation between geomagnetic field disturbances at the cable landing sites and the resultant line voltage changes. Their analysis uncovered a near-linear power law relationship that suggests that the submarine cable systems, as currently designed, would withstand even extreme geomagnetic events without suffering catastrophic damage.

A robust method of continuous voltage monitoring and magnetometer analysis was used to quantify these effects. The measurement of voltage changes was cross-referenced with geomagnetic disturbances recorded at nearby observatories. High-frequency geomagnetic field fluctuations were identified as key drivers of voltage change in the submarine systems.

Results

One of the paper's central findings is the discovery of a scaling law relating line voltage changes to geomagnetic perturbations. The correlation coefficient obtained was 0.97, indicating a strong relationship. The findings suggest that the design features of modern submarine systems, including their dual power feed configurations and power regulation strategies, provide sufficient headroom to accommodate even rare superstorms without irreversible damage to the infrastructure.

Implications

This research provides valuable insights into the resilience of submarine internet cables against geomagnetic disturbances. It dispels previous concerns about large-scale internet outages caused by CMEs by demonstrating the capability of current submarine cable designs to withstand potential solar superstorms. The results are particularly significant given the critical importance of these cables to global communications and economic activities.

The findings also have design implications, suggesting that the principal vulnerability of such infrastructure lies not in the cable's length or orientation but rather in the geoelectric environments near coastal landings. This understanding can inform future designs and standards to ensure that submarine cables remain resilient against space weather.

Future Developments

Though the paper concludes that the primary risk to internet infrastructure from geomagnetic storms is the impact on terrestrial power grids rather than submarine cables, it still highlights the need for continuous monitoring and potential advancements in predictive modeling. Future research could focus on enhancing the precision of geomagnetic storm forecasting and exploring the coastal effects of geomagnetic induction in more detail.

In conclusion, this paper contributes a significant layer of understanding to the discourse on space weather impacts on global communication infrastructure. While reaffirming that current submarine cable systems are robust against severe space weather phenomena, it underscores the importance of comprehensive disaster preparedness strategies that encompass both terrestrial and marine infrastructures.