The Perfect Storm

Entry type: Single project

Country/area: United States

Publishing organisation: Reuters

Organisation size: Big

Publication date: 2022-02-14

Language: English

Authors: Simon Scarr, Manas Sharma


The Reuters graphics team publishes visual stories and data visualisations. The team typically covers all areas of the news, with content ranging from climate change to financial markets. Many of the pieces are conceptualised, researched, and produced by the graphics team.

Project description:

Volcanic eruptions are thought of as giant ash plumes or rivers of flowing lava, but the eruption on the island nation of Tonga on January 15 saw one of the largest volcanic lightning events ever recorded. This project delved into how over a three day period, the area saw 590,000 lightning strikes. Reuters visualised and mapped how the lightning strikes were dispersed across the island skirting the Tonga capital of Nuku’alofa, situated only 65 km (40 miles) south of the eruption. We also explained what caused this phenomenon and took a data-driven look at how this event dwarfed other eruptions.

Impact reached:

The project drew widespread interest and plaudits on social media as it delved into an aspect of the eruption that wasn’t looked at in detail, despite the widespread international interest in the story.

Techniques/technologies used:

The primary tools used were Python and D3 to analyse and build out the visualisations.

Themassive dataset contained coordinates for 590,000 strikes. We used python to clean the data and get into a concise format. We chose to visualise in a gridded format which we could then apply density values and animate cleanly.

Javascript was used to create the animation of the lightning strikes as you scroll through the chronology.

Context about the project:

Tonga by its geographic location is fairly inaccessible. Due to the eruption its communication with the outside world had been severed. There was no easy or apparent way to report from the ground. Yet the story had global importance and as graphics reporters we had to find a way to tell detailed stories about the event despite the challenges.

Another challenge was to turn this large scientific data set into a visualisation that readers can easily digest and understand. We worked closely with a number of scientists in order to make sure our explanations were accurate.

What can other journalists learn from this project?

Despite being a world away, using research, OSINT and satellite mapping, it is possible to report deeply on a story that you may have reporting constraints. In our case it was geographic proximity to the event that was a challenge so we had little information from the ground, but there are multiple ways of getting into a story.

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