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Agua de Pau

Photo of this volcano
  • Portugal
  • Atlantic Ocean
  • Stratovolcano
  • 1564 CE
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 37.77°N
  • 25.47°W

  • 947 m
    3107 ft

  • 382090
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Bulletin Report: March 1989 (SEAN 14:03) Citation IconCite this Report

Seismicity since May 1988 summarized

[Agua de Pau information only; extracted from a summary of significant seismic activity in the E Azores (figure 1) since May 1988.]

Figure (see Caption) Figure 1. Sketch map showing islands in the eastern Azores. Approximate epicenters of the 3-5 October 1988 swarm at the submarine volcano Don Joao de Castro Bank (4) and the 21 November 1988 and 21 January 1989 earthquakes in the Hirondelle Basin (6 and 7) are shown. Courtesy of R. Moore.

"A swarm of microearthquakes, accompanied by weak harmonic tremor, occurred beneath the NE flank of Agua de Pau Volcano on Sao Miguel (figure 2, zone 1) 23-24 May 1988. Seismometers recorded 383 earthquakes; the largest had intensities of MM IV-V in villages along the N coast. A similar but smaller swarm occurred in the same area in 1983 and was recorded by USGS seismographs. Numerous, small, normal faults (including some that show scissor-type movement) displace basaltic, tristanitic, and trachytic vent deposits and flows in this area. However, the area has had no eruptions for about 3,000 years and is the least active of the five volcanic zones on Sao Miguel that have erupted during Holocene time.

Figure (see Caption) Figure 2. Approximate epicenters for earthquakes on and near the island of Sao Miguel, May-October, 1988. Courtesy of R. Moore.

"A small swarm of microearthquakes occurred 24-26 June [1988] on the S flank of Agua de Pau Volcano (zone 2). Sixty-four earthquakes were recorded; the largest had intensities of MM III-IV in nearby villages. No tremor accompanied this episode.

"A small swarm of microearthquakes occurred 6 July [1988] near the S coast of Sao Miguel (zone 3). Fifty-one earthquakes were recorded; the largest was felt and had an intensity of MM III-IV. No tremor accompanied this episode.

Information Contacts: A. Rodrigues da Silva, Consorcio Geotermico de S. Miguel; R. Moore, USGS; National Institute of Meteorology and Geophysics, Portugal.

The Global Volcanism Program has no Weekly Reports available for Agua de Pau.

Bulletin Reports - Index

Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

03/1989 (SEAN 14:03) Seismicity since May 1988 summarized




Information is preliminary and subject to change. All times are local (unless otherwise noted)


March 1989 (SEAN 14:03) Citation IconCite this Report

Seismicity since May 1988 summarized

[Agua de Pau information only; extracted from a summary of significant seismic activity in the E Azores (figure 1) since May 1988.]

Figure (see Caption) Figure 1. Sketch map showing islands in the eastern Azores. Approximate epicenters of the 3-5 October 1988 swarm at the submarine volcano Don Joao de Castro Bank (4) and the 21 November 1988 and 21 January 1989 earthquakes in the Hirondelle Basin (6 and 7) are shown. Courtesy of R. Moore.

"A swarm of microearthquakes, accompanied by weak harmonic tremor, occurred beneath the NE flank of Agua de Pau Volcano on Sao Miguel (figure 2, zone 1) 23-24 May 1988. Seismometers recorded 383 earthquakes; the largest had intensities of MM IV-V in villages along the N coast. A similar but smaller swarm occurred in the same area in 1983 and was recorded by USGS seismographs. Numerous, small, normal faults (including some that show scissor-type movement) displace basaltic, tristanitic, and trachytic vent deposits and flows in this area. However, the area has had no eruptions for about 3,000 years and is the least active of the five volcanic zones on Sao Miguel that have erupted during Holocene time.

Figure (see Caption) Figure 2. Approximate epicenters for earthquakes on and near the island of Sao Miguel, May-October, 1988. Courtesy of R. Moore.

"A small swarm of microearthquakes occurred 24-26 June [1988] on the S flank of Agua de Pau Volcano (zone 2). Sixty-four earthquakes were recorded; the largest had intensities of MM III-IV in nearby villages. No tremor accompanied this episode.

"A small swarm of microearthquakes occurred 6 July [1988] near the S coast of Sao Miguel (zone 3). Fifty-one earthquakes were recorded; the largest was felt and had an intensity of MM III-IV. No tremor accompanied this episode.

Information Contacts: A. Rodrigues da Silva, Consorcio Geotermico de S. Miguel; R. Moore, USGS; National Institute of Meteorology and Geophysics, Portugal.

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Eruptive History

There is data available for 10 Holocene eruptive periods.

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1564 Feb 10 1564 Feb 12 Confirmed 2 Historical Observations Lagoa do Fogo caldera
1563 Jun 28 1563 Jul 26 ± 5 days Confirmed 5 Historical Observations Caldera, NW flank (Cerro Queimado)
0700 ± 150 years Unknown Confirmed   Radiocarbon (uncorrected) WNW flank (Mos)
0160 ± 150 years Unknown Confirmed   Radiocarbon (uncorrected) NW flank (251 m)
1290 BCE (?) Unknown Confirmed 4 Radiocarbon (uncorrected) Lagoa do Fogo caldera
1850 BCE ± 500 years Unknown Confirmed 3 Radiocarbon (uncorrected) East flank (Lagoa do Congro)
2210 BCE ± 150 years Unknown Confirmed   Radiocarbon (uncorrected) East flank (East Congo maar)
2990 BCE (?) Unknown Confirmed 5 Radiocarbon (uncorrected) Lagoa do Fogo caldera and north flank
4550 BCE ± 100 years Unknown Confirmed   Radiocarbon (uncorrected) SW flank (449 m)
6750 BCE ± 200 years Unknown Confirmed   Radiocarbon (uncorrected) West flank (Pico Joao Fernandes)
Deformation History

There is no Deformation History data available for Agua de Pau.

Emission History

There is no Emissions History data available for Agua de Pau.

Photo Gallery

The inner Agua de Pau caldera, seen here from the western caldera rim, is now partially filled by Lagoa do Fogo caldera lake. The caldera was the source of a major explosive eruption about 4,600 years ago that deposited tephra layer Fogo A, and marked the renewal of explosive activity within the approximately 12,000-year-old caldera. The eruption also produced massive pyroclastic flows across most of the volcano’s flanks.

Photo by Rick Wunderman, 1997 (Smithsonian Institution).
Lagoa do Fogo ("Fire Lake") is seen here from the northwest caldera rim of Agua de Pau. A Plinian eruption from the central caldera began on 28 June 1563, depositing trachytic pumice predominantly eastward over the island. On 2 July an eruption began on the northwest flank, producing a lava flow that reached the northern coast at Ribeira Grande.

Photo by Rick Wunderman, 1997 (Smithsonian Institution).
Lagoa do Fogo, seen here from the west, partially fills the younger of two Pleistocene calderas on Agua de Pau stratovolcano in central Sao Miguel Island. The walls of the caldera surrounding the lake rise to a maximum of about 370 m above the surface. Eruptions have occurred both inside the caldera and on the flanks, where multiple cones and domes can be found. Two major explosive eruptions have occurred in the Holocene from the caldera: the Ribeira Cha (8,000 to 12,000 years ago) and Fogo A (about 4,600 years ago).

Photo by Rick Wunderman, 1977 (Smithsonian Institution).
The forested ridge in the center of the photo is part of the northern rim of the approximately 3.2 km diameter inner Agua de Pau caldera, which formed at the beginning of the Holocene, in an eruption dated to between 12,000 and 8,000 years ago. The Serra de Agua de Pau hills in the background mark the northern rim of an outer late Pleistocene caldera. The Lagoa de Fogo caldera lake (lower right) partially fills the inner caldera.

Photo by Rick Wunderman, 1997 (Smithsonian Institution).
A public fountain at Ribeira Grande on the northern coast of San Miguel Island was buried by a lava flow that was erupted from Agua de Pau volcano in 1563. The lava flow originated during the Pico do Sapateiro eruption, which began on 2 July when vents formed across the Queimado dome on the NW flank, generating an eruption column with blocks and bombs. The flank eruption was preceded by a major Plinian eruption from the central caldera that began on 28 June and deposited trachytic pumice dominantly eastward over the island; the summit eruption ended a day after the flank activity began.

Photo by Rick Wunderman, 1997 (Smithsonian Institution).
GVP Map Holdings

The Global Volcanism Program has no maps available for Agua de Pau.

Smithsonian Sample Collections Database

There are no samples for Agua de Pau in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

External Sites