  Tweet hashtags have the potential to improve the search for information
during disaster events. However, there is a large number of disaster-related
tweets that do not have any user-provided hashtags. Moreover, only a small
number of tweets that contain actionable hashtags are useful for disaster
response. To facilitate progress on automatic identification (or extraction) of
disaster hashtags for Twitter data, we construct a unique dataset of
disaster-related tweets annotated with hashtags useful for filtering actionable
information. Using this dataset, we further investigate Long Short Term
Memory-based models within a Multi-Task Learning framework. The best performing
model achieves an F1-score as high as 92.22%. The dataset, code, and other
resources are available on Github.
