2018 November Monthly Report
On November 30th, a magnitude 7 earthquake struck Alaska. The epicenter was about 7 miles from Anchorage and slope failures caused substantial infrastructure damage, primarily to roads such as the Glenn Highway. No loss of life has been reported. This was the most significant quake since the 9.2 magnitude “Good Friday” earthquake in 1964, which killed more than 100 people. Damage from the November 30th quake was comparatively limited, which is being attributed to the deep epicenter (27 miles below the surface) and strict building codes, which were put in place after the 1964 disaster. It is interesting to note that earthquakes can affect weather observations and data quality control needs to be performed on station data accordingly. Figure 5 shows the data recorded at a precipitation gauge in Kenai during the earthquake. The earthquake signal can be seen clearly as an anomalous peak shortly before 9am on November 30th.
November average sea ice extent in the Bering Sea was the lowest in the satellite era. Overall Arctic sea ice extent is currently slightly above the extent at this time of year in 2016 and 2017, although still well below the 1981-2010 normal.
Ash emissions from Veniaminof volcano prompted aviation warnings and air quality advisories on November 21 for the Aleutians. According to the USGS, the ash plume rose up to 15 000 feet and spread about 150 miles to the Southeast.
Drought conditions persist in the Southeast. While precipitation has been around normal during October and November, this has not been enough to compensate for the dry previous months and conditions in the southern part of the panhandle are still classified as D2/severe drought according to the US Drought Monitor (https://droughtmonitor.unl.edu).