The 17 July 2006 magnitude Mw 7.8 earthquake off the south coast of western Java, Indonesia, gene... more The 17 July 2006 magnitude Mw 7.8 earthquake off the south coast of western Java, Indonesia, generated a tsunami that effected over 300 km of coastline and killed more than 600 people, with locally focused runup heights exceeding 20 m. This slow earthquake was hardly felt on Java, and wind waves breaking masked any preceding withdrawal of the water from the shoreline, making this tsunami difficult to detect before impact. An International Tsunami Survey Team was deployed within one week and the investigation covered more than 600 km of coastline. Measured tsunami heights and run-up distributions were uniform at 5 to 7 m along 200 km of coast; however there was a pronounced peak on the south coast of Nusa Kambangan, where the tsunami impact carved a sharp trimline in a forest at elevations up to 21 m and 1 km inland. Local flow depth exceeded 8 m along the elevated coastal plain between the beach and the hill slope. We infer that the focused tsunami and runup heights on the island su...
The 2004 Sumatra-Andaman tsunami flooded coastal northern Sumatra to a depth of over 20 m, deposi... more The 2004 Sumatra-Andaman tsunami flooded coastal northern Sumatra to a depth of over 20 m, deposited a discontinuous sheet of sand up to 80 cm thick, and left mud up to 5 km inland. In most places the sand sheet is normally graded, and in some it contains complex internal stratigraphy. Structures within the sand sheet may record the passage of up to 3 individual waves. We studied the 2004 tsunami deposits in detail along a flow-parallel transect about 400 m long, 16 km southwest of Banda Aceh. Near the shore along this transect, the deposit is thin or absent. Between 50 and 400 m inland it ranges in thickness from 5 to 20 cm. The main trend in thickness is a tendency to thicken by filling low spots, most dramatically at pre-existing stream channels. Deposition generally attended inundation—along the transect, the tsunami deposited sand to within about 40 m of the inundation limit. Although the tsunami deposit contains primarily material indistinguishable from material found on the b...
Shores of eastern Hokkaido rose by perhaps I m a few centuries ago. The uplifted area extended at... more Shores of eastern Hokkaido rose by perhaps I m a few centuries ago. The uplifted area extended at least 50km along the southern Kuril Trench. It included the estuaries Akkeshi-ko and Hichirippu, on the Pacific coast, and Furen-ko and Onneto, which open to the Okhotsk Sea. At each estuary, intertidal and subtidal flats rose with respect to tide level; wetland plants colonized the emerging land; and peaty wetland deposits thereby covered mud and sand of the former flats. Previous work at Akkeshi-ko and Onneto showed that such emergence occurred at least three times in the past 3000 years. Volcanic-ash layers date the youngest emergence to the seventeenth century AD. New evidence from Akkeshi-ko, Hichirippu and Furen-ko clarifies the age and amount of this youngest emergence. Much of it probably dates from the century's middle decades. Some of the newly emerged land remained above high tides into the middle of the eighteenth century or later. The emergence in the last half of the s...
... MCADOO,3 BRUCE JAFFE,4 LORI DENGLER,5 GUY GELFENBAUM,4 BRETWOOD HIGMAN,6 RAHMAN HIDAYAT,7,8,1... more ... MCADOO,3 BRUCE JAFFE,4 LORI DENGLER,5 GUY GELFENBAUM,4 BRETWOOD HIGMAN,6 RAHMAN HIDAYAT,7,8,14 ANDREW MOORE,9 ... in Jakarta preparing to begin a research cruise from Padang in Sumatra, through the islands west of Sumatra, north to Banda ...
Abstract
Sediment cores from Karagan Lagoon in southeastern Sri Lanka retrieved deposits from the... more Abstract Sediment cores from Karagan Lagoon in southeastern Sri Lanka retrieved deposits from the A.D. 2004 Indian Ocean tsunami and older similar deposits that provide evidence for a tsunami 2417 ± 152 cal. (calendar) yr B.P. to 2925 ± 98 cal. yr B.P., and for six tsunamis between 4064 ± 128 cal. yr B.P. and 6665 ± 110 cal. yr B.P., a period for which the sediment record appears continuous. Radiocarbon dating indicates that the recurrence interval is variable, ranging from 181–517 yr to 1045 ± 334 yr, with a mean recurrence interval of 434 ± 40 yr during the ca. 4000–7000 cal. yr B.P. continuous interval. Assuming that these tsunamis were generated by giant earthquakes along the Sumatra-Andaman subduction zone, a reasonable assumption for this far-field transoceanic location, this record extends the giant-earthquake history for the Indian Ocean region. The longest recurrence interval of more than 1000 yr implies that earthquakes along the subduction zone may reach twice the size of the 2004 earthquake.
The 17 July 2006 magnitude Mw 7.8 earthquake off the south coast of western Java, Indonesia, gene... more The 17 July 2006 magnitude Mw 7.8 earthquake off the south coast of western Java, Indonesia, generated a tsunami that effected over 300 km of coastline and killed more than 600 people, with locally focused runup heights exceeding 20 m. This slow earthquake was hardly felt on Java, and wind waves breaking masked any preceding withdrawal of the water from the shoreline, making this tsunami difficult to detect before impact. An International Tsunami Survey Team was deployed within one week and the investigation covered more than 600 km of coastline. Measured tsunami heights and run-up distributions were uniform at 5 to 7 m along 200 km of coast; however there was a pronounced peak on the south coast of Nusa Kambangan, where the tsunami impact carved a sharp trimline in a forest at elevations up to 21 m and 1 km inland. Local flow depth exceeded 8 m along the elevated coastal plain between the beach and the hill slope. We infer that the focused tsunami and runup heights on the island su...
The 2004 Sumatra-Andaman tsunami flooded coastal northern Sumatra to a depth of over 20 m, deposi... more The 2004 Sumatra-Andaman tsunami flooded coastal northern Sumatra to a depth of over 20 m, deposited a discontinuous sheet of sand up to 80 cm thick, and left mud up to 5 km inland. In most places the sand sheet is normally graded, and in some it contains complex internal stratigraphy. Structures within the sand sheet may record the passage of up to 3 individual waves. We studied the 2004 tsunami deposits in detail along a flow-parallel transect about 400 m long, 16 km southwest of Banda Aceh. Near the shore along this transect, the deposit is thin or absent. Between 50 and 400 m inland it ranges in thickness from 5 to 20 cm. The main trend in thickness is a tendency to thicken by filling low spots, most dramatically at pre-existing stream channels. Deposition generally attended inundation—along the transect, the tsunami deposited sand to within about 40 m of the inundation limit. Although the tsunami deposit contains primarily material indistinguishable from material found on the b...
Shores of eastern Hokkaido rose by perhaps I m a few centuries ago. The uplifted area extended at... more Shores of eastern Hokkaido rose by perhaps I m a few centuries ago. The uplifted area extended at least 50km along the southern Kuril Trench. It included the estuaries Akkeshi-ko and Hichirippu, on the Pacific coast, and Furen-ko and Onneto, which open to the Okhotsk Sea. At each estuary, intertidal and subtidal flats rose with respect to tide level; wetland plants colonized the emerging land; and peaty wetland deposits thereby covered mud and sand of the former flats. Previous work at Akkeshi-ko and Onneto showed that such emergence occurred at least three times in the past 3000 years. Volcanic-ash layers date the youngest emergence to the seventeenth century AD. New evidence from Akkeshi-ko, Hichirippu and Furen-ko clarifies the age and amount of this youngest emergence. Much of it probably dates from the century's middle decades. Some of the newly emerged land remained above high tides into the middle of the eighteenth century or later. The emergence in the last half of the s...
... MCADOO,3 BRUCE JAFFE,4 LORI DENGLER,5 GUY GELFENBAUM,4 BRETWOOD HIGMAN,6 RAHMAN HIDAYAT,7,8,1... more ... MCADOO,3 BRUCE JAFFE,4 LORI DENGLER,5 GUY GELFENBAUM,4 BRETWOOD HIGMAN,6 RAHMAN HIDAYAT,7,8,14 ANDREW MOORE,9 ... in Jakarta preparing to begin a research cruise from Padang in Sumatra, through the islands west of Sumatra, north to Banda ...
Abstract
Sediment cores from Karagan Lagoon in southeastern Sri Lanka retrieved deposits from the... more Abstract Sediment cores from Karagan Lagoon in southeastern Sri Lanka retrieved deposits from the A.D. 2004 Indian Ocean tsunami and older similar deposits that provide evidence for a tsunami 2417 ± 152 cal. (calendar) yr B.P. to 2925 ± 98 cal. yr B.P., and for six tsunamis between 4064 ± 128 cal. yr B.P. and 6665 ± 110 cal. yr B.P., a period for which the sediment record appears continuous. Radiocarbon dating indicates that the recurrence interval is variable, ranging from 181–517 yr to 1045 ± 334 yr, with a mean recurrence interval of 434 ± 40 yr during the ca. 4000–7000 cal. yr B.P. continuous interval. Assuming that these tsunamis were generated by giant earthquakes along the Sumatra-Andaman subduction zone, a reasonable assumption for this far-field transoceanic location, this record extends the giant-earthquake history for the Indian Ocean region. The longest recurrence interval of more than 1000 yr implies that earthquakes along the subduction zone may reach twice the size of the 2004 earthquake.
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Sediment cores from Karagan Lagoon in southeastern Sri Lanka retrieved deposits from the A.D. 2004 Indian Ocean tsunami and older similar deposits that provide evidence for a tsunami 2417 ± 152 cal. (calendar) yr B.P. to 2925 ± 98 cal. yr B.P., and for six tsunamis between 4064 ± 128 cal. yr B.P. and 6665 ± 110 cal. yr B.P., a period for which the sediment record appears continuous. Radiocarbon dating indicates that the recurrence interval is variable, ranging from 181–517 yr to 1045 ± 334 yr, with a mean recurrence interval of 434 ± 40 yr during the ca. 4000–7000 cal. yr B.P. continuous interval. Assuming that these tsunamis were generated by giant earthquakes along the Sumatra-Andaman subduction zone, a reasonable assumption for this far-field transoceanic location, this record extends the giant-earthquake history for the Indian Ocean region. The longest recurrence interval of more than 1000 yr implies that earthquakes along the subduction zone may reach twice the size of the 2004 earthquake.
Sediment cores from Karagan Lagoon in southeastern Sri Lanka retrieved deposits from the A.D. 2004 Indian Ocean tsunami and older similar deposits that provide evidence for a tsunami 2417 ± 152 cal. (calendar) yr B.P. to 2925 ± 98 cal. yr B.P., and for six tsunamis between 4064 ± 128 cal. yr B.P. and 6665 ± 110 cal. yr B.P., a period for which the sediment record appears continuous. Radiocarbon dating indicates that the recurrence interval is variable, ranging from 181–517 yr to 1045 ± 334 yr, with a mean recurrence interval of 434 ± 40 yr during the ca. 4000–7000 cal. yr B.P. continuous interval. Assuming that these tsunamis were generated by giant earthquakes along the Sumatra-Andaman subduction zone, a reasonable assumption for this far-field transoceanic location, this record extends the giant-earthquake history for the Indian Ocean region. The longest recurrence interval of more than 1000 yr implies that earthquakes along the subduction zone may reach twice the size of the 2004 earthquake.