Although extreme events are inevitable, the associated cost to infrastructure and human life is not. We can mitigate these costs through improving the information available to emergency responders during and after crisis events via social media. Recent research has identified a correlation between spikes of Twitter activity and the infrastructural damage incurred during natural disasters. This research, however, overlooks emergencies occurring in areas in which people have lost power, lack the ability to connect to the internet, or, due to differences in social media perceptions, are uncompelled to Tweet during a disaster. To assess the prevalence of Twitter activity decreases and the relative importance of those decreases in detecting areas in crisis, we study crisis-driven Twitter activity deviations from “normal” in nine cities affected by the 2017 Atlantic hurricane season. In analyzing more than 1.1 million Tweets across the season, we find that there is a stronger, more significant correlation between infrastructure damage and a metric that prioritizes both increases and decreases in Twitter activity than one that prioritizes only Twitter activity increases. These findings indicate that social media drop-offs could be representative of significant distress, and accounting for the apparent survivorship bias in social media will be critical to the equitable use of social media in crisis applications.

尽管极端事件是不可避免的，但基础设施和人类生命的相关成本却并非不可避免。我们可以通过社交媒体改善危机事件发生期间和之后提供给应急人员的信息，从而降低这些成本。最近的研究已确定Twitter活动的峰值与自然灾害期间造成的基础设施破坏之间的相关性。但是，这项研究忽略了人们失去权力，缺乏连接互联网的能力或由于社交媒体观念上的差异而在灾难期间不被推特的地区发生的紧急情况。为了评估Twitter活动的流行程度以及这些活动的减少在发现危机区域中的相对重要性，我们研究了受2017年大西洋飓风季节影响的9个城市中受危机驱动的Twitter活动偏离“正常”状态的情况。在分析整个季节超过110万条推文时，我们发现与仅优先考虑Twitter活动增加的推特相比，基础设施损害与优先考虑Twitter活动的增加和减少的指标之间存在更强大，更重要的关联。这些发现表明，社交媒体的流失可能是严重困扰的代表，并且考虑到社交媒体中明显的生存偏见对于在危机应用中公平使用社交媒体至关重要。与仅优先考虑Twitter活动增加的指标相比，基础架构损害与优先考虑Twitter活动的增加和减少指标的指标之间的相关性更大。这些发现表明，社交媒体的流失可能是严重困扰的代表，并且考虑到社交媒体中明显的生存偏见对于在危机应用中公平使用社交媒体至关重要。与仅优先考虑Twitter活动增加的指标相比，基础架构损害与优先考虑Twitter活动的增加和减少指标的指标之间的相关性更大。这些发现表明，社交媒体的流失可能是严重困扰的代表，并且考虑到社交媒体中明显的生存偏见对于在危机应用中公平使用社交媒体至关重要。