You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Guam

Context:
The island of Guam is 30 miles (50 km) long and 4 to 12 miles (6 to 19 km) wide, 3⁄4 the size of Singapore. The island experiences occasional earthquakes due to its location on the western edge of the Pacific Plate and near the Philippine Sea Plate. In recent years, earthquakes with epicenters near Guam have had magnitudes ranging from 5.0 to 8.7. Unlike the Anatahan volcano in the Northern Mariana Islands, Guam is not volcanically active. However, due to its proximity to Anatahan, vog (i.e. volcanic smog) does occasionally affect Guam.

Question:
What natural disaster that is not predictable does Guam have to worry about?

earthquakes