{"id":1551,"date":"2024-03-12T11:43:24","date_gmt":"2024-03-12T10:43:24","guid":{"rendered":"https:\/\/www.gis-hub.uzh.ch\/?p=1551"},"modified":"2025-12-18T11:09:37","modified_gmt":"2025-12-18T10:09:37","slug":"there-are-hot-spots-of-wrecks-in-places-i-did-not-expect","status":"publish","type":"post","link":"https:\/\/www.gis-hub.uzh.ch\/en\/there-are-hot-spots-of-wrecks-in-places-i-did-not-expect\/","title":{"rendered":"\u201cThere are hot spots of wrecks in places I did not expect\u201d"},"content":{"rendered":"\n

What can shipwrecks of the 19th century in the Indian Ocean tell us about the climate of the past? And what can the records of these wrecks tell us about climate knowledge production? In her research, Debjani Bhattacharyya, Professor for<\/strong> the History of the Anthropocene at the Department of History at UZH, explores these questions as part of a large-scale project.<\/strong><\/p>\n\n\n\n

\u201cHistorical climatology commonly looks at diurnal weather recordings such as weather diaries or farmer almanacs to gather information about the weather and the climate in the past,\u201d says Debjani Bhattacharyya, Professor for the History of the Anthropocene at the Department of History at UZH. But she is interested in completely different sources, she explains: \u201cWe call them \u2018weather genres\u2019 and by that, we mean all sorts of non-traditional, non-scientific sources which have been ignored so far by historians.\u201d Examples are imperial finances or oceanic trade. \u201cThey contain a lot of information about weather disasters e.g., thanks to hail insurance claims,\u201d Debjani adds. While looking for weather genres, Debjani came across the wreck records in the Indian Ocean, produced annually from 1864 to 1940 and containing 700 to 800 pages each, including maps.<\/p>\n\n\n\n

The potential of long-term annual maps<\/strong>
Initially, Debjani just studied the maps in the annual wreck records without considering digitising them. She was mainly interested in the records as legal cases since she detected that the clerks who were compiling the cases developed a typology of wrecks: \u201cThey distinguished between wrecks and casualties, thus between natural and human causes of the wrecks.\u201d Of course, with her focus on weather and climate, she was more interested in the wrecks.<\/p>\n\n\n

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Figure 1: Legend belonging to the map in the wreck records of 1883 (source: The British Library)<\/em>.<\/figcaption><\/figure>\n<\/div>\n\n\n

\u201cIt was only when I gave a lecture at the New York University and historian, David Ludden, who was working on Indian ports pointed out that most people did not know that this sort of data existed for the Indian Ocean,\u201d she says. Only then Debjani became aware of the potential that the maps hold: \u201cWith climate change playing havoc in the Indian Ocean at the moment, I thought that these records could help to get a picture of the dynamic change over almost 80 years they cover.\u201d She was curious to find out if maps could tell her something more or different compared to the written accounts of these cases: \u201cFor instance, what sort of weather events can we glean from these maps? Or is there a preponderance of wrecks in a place I wasn\u2019t expecting?\u201d<\/p>\n\n\n\n

Expected and unexpected hot spots<\/strong>
The printed maps for each year in the original record cover the entire Indian Ocean. Each ship is approximately mapped to where the wreck or casualty happened. In some cases, however, there is not enough space on the paper map to locate all the wrecks correctly. The wrecks are then lined up towards the ocean or the mainland (see images below). Additional information on the location and the circumstances of a wreck can be found in the written records.<\/p>\n\n\n

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Figure 2: On the map of 1883, there are more ship casualties (blue symbols) in Mumbai (Bombay) Harbour than there is space on the map (source: The British Library).<\/em><\/figcaption><\/figure>\n<\/div>\n\n
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Figure 3: On the map of 1883, upstream of Hooghly River, especially around Kolkata, ships are mapped on the mainland (source: The British Library).<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n

In the beginning, Debjani had no expectations for the digitised map: \u201cI had a clean mind and was curious to know what the digitised maps could teach me about the material I know.\u201d Yet, this changed once she saw the first year mapped in digital form by the GIS Hub (open map in new tab<\/a>):<\/p>\n\n\n\n