Catalogue of Violent and Destructive Earthquakes in the Philippines: With an Appendix: Earthquakes in the Marianas Islands 1599-1909

In Short

This work is a systematic historical catalog documenting the seismic history of the Philippines and the Mariana Islands from 1599 to 1909. Written by a Jesuit meteorologist in response to an international scientific request, it records centuries of tremors, ground fissures, and structural collapses. It outlines how early Spanish architectural mistakes led to catastrophic leveling, forcing a total redesign of public buildings across the archipelago. The volume endures as a foundational repository of primary historical data, offering modern readers and seismologists an unvarnished timeline of disaster, human adaptation, and structural resilience in the Western Pacific.

The Story

The text unfolds as a rigorous historical and scientific accounting of seismic phenomena in the Philippine archipelago and the neighboring Marianas. The narrative progression begins with a clear research imperative: famous British seismologist John Milne requested a localized list of high-intensity earthquakes to complete a global catalog under the auspices of the British Association for the Advancement of Science. Father Miguel Saderra Masó takes this basic directive and expands it into a comprehensive record using the De Rossi-Forel scale, aiming to preserve crucial regional context, casualty counts, and localized structural damage that terse global registries omit.

The historical trajectory starts in 1599, the earliest date recorded in the Spanish colonial chronicles. In the initial decades following Miguel López de Legazpi’s arrival, native architecture relied primarily on timber framing and palm leaf thatch. While these flexible, lightweight structures resisted earthquake damage, they repeatedly succumbed to disastrous urban fires. Driven by a desire to protect the young capital, Bishop Domingo de Salazar spearheaded a massive push toward stone and brick construction. Throughout the late sixteenth and early seventeenth centuries, Manila transformed into a magnificent city of heavy tile-roofed palaces, imposing cathedrals, and lofty masonry towers built without adequate seismic precautions.

This period of architectural hubris meets a catastrophic resolution on November 30, 1645. The Great St. Andrew earthquake razes the heavy stone city to the ground, killing hundreds and fundamentally shifting Spanish colonial engineering. From that moment forward, building codes across the islands adapt, abandoning top-heavy stone designs in favor of lower, reinforced styles that dramatically improve survival rates in subsequent centuries.

The work then shifts to a region-by-region catalog, utilizing detailed mapping schemes, seismic intensity indices, and regional fault-line classifications. Saderra Masó systematically itemizes centuries of tremors, recording damage to parish churches and conventos—often the only heavy masonry structures present in outlying rural provinces—along with reports of coastal land displacements, sea disturbances, and long series of aftershocks. The book concludes with a dedicated appendix documenting parallel seismic events in the Mariana Islands, tracking major disasters on Guam and Saipan up through 1909 to complete a broad, connected record of regional tectonic activity.

How It Unfolds

The scientific mandate Father Saderra Masó establishes the purpose of the volume as a response to John Milne’s global earthquake survey. He explains the decision to retain the De Rossi-Forel intensity scale rather than Milne’s condensed categories, ensuring local historical details are preserved.

The transformation of Manila The narrative recounts how early wood-and-thatch Manila repeatedly burned, prompting Bishop Domingo de Salazar to introduce stone quarries and masonry building. Over fifty years, Spanish builders construct grand, heavy palaces and tall churches without considering seismic risks.

The St. Andrew's Day ruin In 1645, a massive earthquake strikes Manila on the feast of St. Andrew, reducing the stone metropolis to rubble. This disaster forces a permanent revolution in Philippine architecture, shifting future construction toward flexible, low-slung, and seismically safer designs.

Mapping the seismic zones The text introduces detailed geographical charts using Roman numerals, ordinal indices, and star markers to denote epicenters and regional fault lines. This section bridges raw chronicle history with modern spatial analysis for future earthquake researchers.

The provincial record The catalog moves systematically through the provinces, relying heavily on damage reports from parish churches and conventos. Because these religious compounds were the most substantial masonry structures in rural towns, their destruction serves as the benchmark for shock intensity.

The Mariana Islands appendix The catalog closes with an inventory of earthquakes in Guam and Saipan from 1825 to 1903. It tracks severe shocks that opened ground fissures, caused ocean anomalies, and repeatedly leveled stone churches and government halls in Agaña.

The People

Rev. Miguel Saderra Masó The author and Assistant Director of the Manila Central Observatory approach the historical record with scientific rigor. Driven by a desire to contribute to global seismology while preserving local history, he compiles scattered monastic chronicles, government logs, and scientific readings into a unified reference text.

Prof. John Milne The eminent British seismologist acts as the catalyst for the entire volume. Working under the British Association for the Advancement of Science, his push to create a standardized global earthquake catalog prompts the Manila Observatory to organize its historical data.

Bishop Domingo de Salazar The first Bishop of Manila plays a central role in the city's early architectural development. Distressed by devastating urban fires that routinely destroy thatch buildings, he personally searches the countryside for stone quarries, launching a decades-long building boom that ultimately leaves Manila vulnerable to the disaster of 1645.

The Spanish Chroniclers The unnamed colonial historians and friars whose early records survive the centuries provide the foundation for the text. Their detailed observations regarding structural failures, land movements, and recovery efforts allow Saderra Masó to reconstruct centuries of uninstrumented natural disasters.

In Its Own Voice

When describing the tragic architectural choices made during the early decades of Spanish rule in Manila, the chroniclers record the city's fleeting, dangerous splendor:

"Beautiful structures and dwelling houses were reared, so high and spacious that they resembled palaces; magnificent churches with lofty and graceful towers, within the walls of Manila as well as outside of them: all of which made the city very beautiful and gay and contributed equally to health and pleasure."

Explaining why religious parish buildings dominate the damage reports throughout the island provinces, the author clarifies a key architectural context:

"This is easily explained by the fact that these buildings were often the only structures within the meizoseismal area, and built nearly everywhere in the most substantial manner."

In documenting the catastrophic 1849 earthquake in the Mariana Islands, the tabular record notes the sudden geological and maritime upheavals:

"Immense fissures opened in many places, and an extraordinary commotion of short duration was observed in the sea."

What It's Really About

At its core, the text explores the tension between human built environments and immutable natural forces. Beyond its primary function as a scientific index, the book illustrates how human societies learn from ecological disaster. The historical pivot from flammable thatch to rigid stone, and finally to flexible, low-profile architecture demonstrates a brutal, centuries-long iteration of trial and error. The work also highlights the vital role of local institutions—specifically the Manila Observatory and colonial parish network—in preserving long-term scientific memory across isolated island populations.

Why Read It Today

This book appeals to historians of science, geologists, and readers fascinated by the colonial Pacific. Reading it feels like sitting down with a meticulously organized archive where stark historical facts tell an implicit story of human vulnerability. Saderra Masó’s writing is clean, direct, and free of unnecessary melodrama, letting the weight of primary data carry the narrative.

The reader must navigate dense statistical tables, repetitive technical descriptions, and period terminology—such as the persistent use of the word convento to describe parish rectories. However, these difficulties are offset by the vivid glimpses of colonial life and sudden disaster preserved in the text. The chronicle of Manila's early rise and fall, alongside the stark tabular entries describing crumbling towns, retreat of the sea, and months of continuous aftershocks, leaves a lasting impression of the fragility of human settlement along the Ring of Fire.