Role of Social Media in Earthquake: A Systematic Review

Nowadays, information performs a peculiar role in effective crisis management, and social media is one of the new sources of information for disaster relief organizations, enhancing situational awareness and mutual communication (1). Moreover, these media can contribute greatly to people's communication in times of crisis and disaster (2). Since these media are interactive digital or mobile-based tools, they can allow users to produce new content, access information, and influence available content (3). Social media can be used either as a communicative or information dissemination tool during disasters in crisis management (4). The effective use of social media in both ways may reduce the effects of disaster (5). Therefore, effective use of social media in crisis management leads to increased acceptance of management strategies and improvement in disaster management programs (6).

However, serious obstacles are posed to the use of social media in the dissemination of important information. In many cases, the high volume of information may not be relevant or useful (7) since it is not entirely relevant to the location of the incident or does not address the involved people (8, 9). Lack of communication or poor communication among respondents can also increase the burden of problems rather than facilitating them (10). In addition, social factors, such as gender, ethnicity, income, and geographic location can influence easy access to social media and other online resources (11-13). The reliability of information created or shared through social media during disasters can also be questioned (10) since information dissemination does not require authentication, and most people do not publish the sources of original data (9, 14, 15).

Although people still rely heavily on mainstream media, such as television and radio, to obtain information about the crisis, their trust in social media has gradually increased (16). For instance, during the Sandy Storm in 2012, about 800,000 photos were published with the hashtag #Sandy on Instagram. These photographs also showed their geographical location (1). In the 2015 Haiti earthquake, various digital crisis management tools were used which released around 1,500 reports showing the affected areas and the number of victims on the map, and they were widely used by US Red Cross and the Haitian government in their operations (17). Therefore, these media play an important role in crisis control.

There has been a wealth of research on the role of social media in earthquakes in recent years, and the number of these studies has been on a rise. The results of the present study can be applied by managers in crisis management. As a systematic review, the current research aimed to analyze the effective role of social networks in earthquakes.

2.1. Search Strategy

This systematic review method was conducted on the related research papers regarding the role of social media in crisis and disaster. To this end, a query was conducted on reputable databases, including Embase, Web of Science, Scopus, and Cochrane within 2019-2000 to retrieve articles on the role of social media in earthquakes using the keywords of natural disaster, earthquake, and social media and Boolean Operators ( AND/ OR). Some Examples of search performed on the Web of Science database were in the following states:

TS= (("Natural disaster" OR "Natural disasters" OR earthquakes OR Earthquake OR Disaster) AND ("Social media" OR "social network" OR "social networking" OR "social software" OR "social medium" OR "social web" OR "web 2.0" OR "web2" OR microblog OR weblog OR blog OR Blogging OR Facebook OR YouTube OR Twitter OR tweet OR Internet OR WeChat OR Skype OR WhatsApp OR Viber OR Messenger OR Instagram OR Telegram)). 

2.2. Assessment of the Recovered Documents

Duplicate results were removed after searching the target databases using Endnote software (version 8). Following that, the researcher again manually reviewed the recovered documents to ensure the removal of all the duplicates. After removing the overlaps, the title and abstract of all retrieved documents were initially reviewed by the researcher. In the second stage, after retrieving the file, the texts of the available articles were reviewed by the researcher.

The inclusion criteria entailed: 1) articles published in English, 2) research papers, conferences, reviews, reports, and commentaries, 3) articles that were thematically focused on the role of social networks in earthquakes, 4) articles released from 2019 to the end of August 2000. On the other hand, the exclusion criteria were as follows:  1) articles published in languages ​​other than English, 2) letter to the editors, editorial articles, 3) articles that were not related to the question and purpose of the research, 4) articles that focused on computational methods for simulation.

The quality of the selected articles was assessed with Strobe and Coreq checklists 

2.3. Data extraction

After the final selection of articles, information was extracted from the full text articles. This information was divided into two separate sections. The first part of the bibliographic information of the articles included the title of the article, the year of publication, the first author, and the title of the journal. In the second part, based on the objectives of the research, the related topic results mentioned in the articles were extracted. 

2.4. Data analysis

Finally, each selected study was carefully read to identify the key concepts and themes. After the completion of the data extraction table, the researcher shared the extracted concepts with other members of the research team, and finally, an agreement was reached among all the members.

Figure 1. Levels of search and selection of articles (flow diagram)

information that is lost during a disaster.

Nonetheless, in the hours after the earthquake (up to 72 h), the release of information is based on the provision of relief goods or services. After 72 h (when communication is established), the information is transmitted more slowly. Finally, in the next stages of information (4-7 months after the earthquake), information about medical, treatment, and financial assistance will be published. It is worth noting that in times of rescue, users mostly re-send other people's posts.

The main category of requests included the three main themes of requesting help to save people, financial assistance, as well as medical items, food, and water. After the earthquake, rescuing people trapped under the rubble is a matter of concern for the survivors of the disaster. In this regard, messages were posted and reposted by people on social media, including Twitter, asking for help to search for people and save their lives. In addition, in the days following the earthquake, messages were sent asking for financial resources, as well as medical items and food, and tweets containing messages asking for action, searching for people, and asking those at the top for help.

The main category of data storage and retrieval consisted of four main themes. The findings illustrated that the information in messages posted by people after such events as earthquakes can be used for future crises and relief. Moreover, it is possible to prepare a map of the affected areas to help evacuate people from the damaged centers and buildings using the available information and tracking where these messages have been published on social media. Furthermore, the stored information can be used for the development of an emergency response system in case of earthquakes or subsequent crises.

This systematic review indicated that social media in disaster relief is a hot research topic in recent years. The roles played by social media in earthquakes can be examined in four main areas: identification, information, requests, as well as the storage and retrieval of information. Based on the findings of related studies, one of the crucial roles of social media in the event of disasters and accidents is the identification and rescue of injured and missing people. In this regard, Henríquez-Coronel et al. stated that after an earthquake, tweets containing messages suggesting identification measures to search for individuals and ask for help were at the top of the messages (17). In the same context, Gray et al. assessed the role of social media during the Nepal earthquake and reported that the hashtag #rescue was extensively used to communicate and try to rescue injured and missing people (18).

Furthermore, another role of social media in the discussion of identification has been the recognition of the medical and nutritional needs of individuals. In this regard, Basu examined the WhatsApp messenger during the Nepal earthquake and demonstrated that the most common use of WhatsApp was the identification of the needs of various resources and delays in sending these resources (19, 20). Along the same lines, Nagamatsu reported observations by Japanese physicians from the first month after the 2011 earthquake. The results of the mentioned study indicated that they used new technologies, such as email lists, and social media, such as Twitter, to send messages such as "water, food, and "The drug will run out by tomorrow,”.

Another role identified for post-crisis social media in studies belonged to information. One of the most useful information is related to the incident, its severity, the amount of initial damage caused by the earthquake, and the subsequent problems or limitations. In this regard, the results of a study conducted by Gray et al. pointed out that the hashtags #earthquake and #Tsunami have been widely used to inform the primary media about the incident. Moreover, in general, the use of the hashtag #government means political unrest. Nonetheless,  in the time of disasters, it refers to the expansion of governmental information in the event of an earthquake, and this hashtag was used to raise awareness in the security and status assessment group (22, 18).

In the same context, the results of a study performed by Yamada et al. suggested that the proper use of appropriate hashtags in tweets is beneficial for anyone who wants to follow disaster information in a particular area (23). In their study, Li et al. noted that damage information was the most commonly used dissemination of information in the 24 h after the earthquake (24). In a similar vein, Maceda et al. reviewed and analyzed Filipino tweets about the earthquake and found that most tweets were about the event, the feeling of the earthquake, the effects of the earthquake, the affected places, and the magnitude of the earthquake. Moreover, the main topics of the messages were related to the magnitude, feeling of the earthquake, and the effects of the earthquake (25).

Malasig and Quinto also examined tweets related to the 2015 Nepal earthquake three days after the quake. They concluded that most of the concepts derived from users' communication behavior in the face of problems and constraints. In their study, Radianti et al. assessed Twitter messages in the Nepal earthquake that contained messages of public concern about the state of the country. The results of the stated study suggested that one of the most prominent issues in people's messages was problems with providing services to victims and airport problems. In this country, there were health problems and rumors (27).

Furthermore, in the field of information, another role of social media was related to warnings. After reviewing Twitter messages, Maceda et al. concluded that information alert was one of the features of social media used by people and governments after the earthquake (25). In the same context, in their study, Gary et al found that the use of the hashtag #HMCS Vancouver referred to the events that HMCS Vancouver helped with crisis management strategies in local areas. In fact, this hashtag indicates warnings through news channels and media (22).

Finally, another role of social media was the provision of information on health-related topics. These roles include information about medical and pharmaceutical issues, one's own health and that of others, medical and relief services, post-crisis measures, such as keeping calm, reducing anxiety, and staying away from high-risk areas, as well as inquiring about missing or dying people. Health and wellness are among the most important issues to consider during and after an earthquake in an area. The devotion of assiduous attention to the health of earthquake survivors, relief and medical measures, as well as helping them to stay calm, are some of the measures that can reduce the subsequent problems.

In a survey of Japanese students on the role of social media during an earthquake, they cited Facebook and Twitter as the most common source of information about their health and sharing their public opinion (28). It also examined post-earthquake Twitter messages in China in the post-earthquake hours (up to 72 hours) by information dissemination based on information about the delivery of relief goods or services. Moreover, the findings showed that people used social media as a source of information to reduce their anxiety about the information that is lost during a disaster (24).

Furthermore, after reviewing and analyzing the messages posted on social media after the earthquake in Mexico, the authorities' recommend-dations regarding immediate measures in the early moments of the crisis, such as keeping calm, not using landlines, and staying away from high-risk areas, were conveyed to people via Twitter (17). On the other hand, the findings of the study by Nagamatsu revealed that information about the intensive care unit activities of hospitals, hemodialysis capacity, and mechanical fans in the first 48 h after the earthquake was provided to the authorities through the website of the Japan Intensive Care Association using Google Map.

In addition, resources and facilities regarding medical and pharmaceutical services, as well as patient transfer based on information obtained from social media, were evaluated(21). According to the aforementioned issues, social media can play a crucial and diverse role in the field of information. It can increase the accuracy of decisions, prevent secondary crises, minimize the presence of non-operational people in the affected area, and ultimately leads to a marked increase in the accuracy and speed of the measures taken by the rescue forces.

In terms of requests, the research findings showed that most of the requests were related to asking for help to save people, financial help, as well as food and water. The experience of numerous earthquakes around the world has demonstrated that after an earthquake, the request for help to save lives increases due to the caused damages. Moreover, the majority of people and governments need financial assistance due to the severity of the damage. In addition, due to the inflicted damages and the lack of resources, the demand for food resources, especially water, has been very high. The results of the analysis of messages posted on social media to help the victims of the earthquake in Nepal showed that one of the most common messages sent to people was the request for financial aid (financial support) and water (27). Another study on the aftermath of the Mexican earthquake and the role of social media reported that most messages in the early hours after the disaster revolved around asking for resources and helping search for people (17). It indicates that social media can be used as a suitable capacity in the field of collecting requests in the affected area to prioritize the deployment of teams and sending shipments with the least possible error.

Another issue that emerged from the findings of the current study was the role of social media in the storage and retrieval of information. In this regard, the information obtained from the messages posted on social media after a disaster, such as an earthquake, can be used for subsequent crises, relief, mapping the affected areas and evacuation centers, and the development of an emergency response system. In their study, Croocks et al. demonstrated that the social media information (Twitter) stored in a system, such as the website of the US Geological Survey, can be used in times of crisis and relief for future events (29). Caragea et al. referred to the creation of a reusable information technology infrastructure called advanced messaging. The components of this infrastructure include: 1) an iPhone application, 2) a Twitter crawler component, 3) machine translation, and 4) automatic message classification (34). In another study, it was found that the usability of the search method in the Twitter social media can help the development of ontology about evacuation centers which will help to quickly evacuate people from the centers (33).

Other studies have pointed to the role of this information in rescuing people (35). In a study, a service and a mobile application mediated a tool, such as citizen messages, through the Twitter server to retrieve messages from citizens living in earthquake-stricken areas to be stored and processed in a geographic database using SQL, and it accelerated relief (30). Moreover,  in a study performed by Gautam and Basaua, vector models were used to process text and statistics in order to categorize the information contained on Twitter in order to retrieve information and assist in efforts made to rescue and save lives (31). Social aspects in terms of retention of recorded information, the ability to transfer data to other databases for data analysis, and optimal use, such as drawing different maps (affected areas and emergency accommodation.) with proper planning can maximize the quality of earthquake relief.

Regarding the importance of social media and its crucial role in critical situations, especially earthquakes, the present study indicated that social media can serve as a bridge to receive and disseminate information between victims and others or as a tool to be used in earthquake management due to the different capacities of social media, such as the possibility of access to information, producing new content, and influencing existing content. Based on the available literature, these roles can be assigned to four main sections, including identification, notification, requests, as well as storage and retrieval of information. Successful experiences of using social media in earthquakes in Haiti, Mexico, China, and Nepal highlighted the importance of social media and its role in crisis situations, especially earthquakes. Consequently, social media as one of the powerful tools in crisis management should receive more assiduous attention.

Conflicts of Interest: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding/Support: The author(s) received no financial support for the research, authorship, and/or publication of this article

Ethical considerations: Ethical approval was granted by theIRAN National Committee for Ethics in Biomedical Research(IR.KMU.REC.1398.107).