## 3 Results and Discussion
### Operation  
The record of continuous days of operation achieved by the Cryologger ITBs and suspected causes leading to the failure of the beacon is shown in Table 3. Lifespans greatly exceeded expectations, with v1.0 beacons deployed in 2018 ranging from 310 days to 4 years,  
Figure 6: Iceberg drift observations recorded by Cryologger ITB deployments made during the 2018 field season. Figure 7: Iceberg drift observations recorded by Cryologger ITB deployments made during the 2019 field season. and v2.0 beacons deployed in 2019 ranging from 333 days to 4 years 70 days, with one beacon still active as of December 2023. The most frequent causes of loss of communication with the ITBs were the eventual deterioration (calving or rolling) or catastrophic breakup of the iceberg and subsequent destruction of the beacon. In many cases, it was possible to use remote sensing imagery to observe major breakup events of icebergs that immediately resulted in transmissions from the beacon ceasing. Data collected from the onboard sensors provided valuable information to assess the overall operation of the beacons and determine the environmental conditions to which they were exposed. Figure 8 displays diagnostic variables recorded from ITB 300434063415110, deployed in 2018, which are considered typical. Sensors monitoring the interior conditions of the enclosures (not necessarily representative of the ambient air temperature) revealed that temperatures regularly dropped below \(-25\)\({}^{\circ}\)C during the winter months and reached as low as \(-40\)\({}^{\circ}\)C (Figure 8a). Under these conditions, the minimum battery voltages were also recorded (Figure 8e), decreasing as low as 6.0 V, but once temperatures increased, voltages quickly returned to nominal (7.2 V). The GNSS receivers were consistently able to track 8 or more satellites and quickly acquired position fixes, impressive considering they only support the Global Positioning System (GPS) constellation; however, during the winter months, fewer satellites were observed (Figure 8c) likely due to the presence of snow cover. Satellite transmissions were very efficient, thanks to the high number of Iridium satellites converging at the North Pole, with most messages transmitting in less than 10 s (Figure 8d). However, issues such as snow cover or a sub-optimal orientation of the beacon enclosure could drastically increase transmission times. The orientation of the beacon was confirmed using the accelerometer pitch and roll angles, with Figure 8b showing three separate instances of roll angles of \(\pm 180^{\circ}\), indicating the beacon had become inverted. The orientation, together with the delayed transmission times (i.e., \(>\)180 s), became good indicators of when the iceberg may have deteriorated and/or the beacon had become dislodged from the iceberg's surface. An interesting discovery from the data recorded from beacon 300434063418130, situated on a grounded iceberg in a fjord along the southern coast of Baffin Island, revealed that the accelerometer detected a repeating signal that varied in both frequency and magnitude. When the daily pitch (Figure 9a) and roll (Figure 9b) measurements were examined over a month and compared with predicted tidal heights (Figure 9c) at Cape Dyer, Nunavut, approximately 150 km from the beacon's position, it was found to be in phase with the diurnal and lunar-phase components of the tidal cycle. That the accelerometer was sensitive enough to detect variations in the pitch and roll of only 1-2\({}^{\circ}\) is a testament to the suitability of new low-cost sensors for measuring the orientation of icebergs and studying the movement of icebergs within three-dimensional space. Although the majority of ITBs experienced nominal operation throughout their lifespans, a small number of issues were discovered in both versions. In v1.0, erroneous temperature and pressure measurements were recorded by four beacons, sporadically affecting approximately 0.5% of observations.