Geology topics

Martitia P. Tuttle

Publications and source records attributed to Martitia P. Tuttle.

7 recordsLinked to original sources

USGS2021

The liquefaction record of past earthquakes in the Central Virginia Seismic Zone, Eastern United States

Following the 2011 moment magnitude, M "> M M 5.7 Mineral, Virginia, earthquake, we conducted a search for paleoliquefaction features and found 41 sand dikes, sand sills, and soft‐sediment deformation features at 24 sites exposed in cutbanks along several rivers: (1) the South Anna River, where paleoliquefaction features were found in the epicentral area of the Mineral earthquake and farther downstream to the southeast; (2) the Mattaponi and Pamunkey Rivers east of the Fall Line, where liquefiable sediments are more common than in the epicentral area; and (3) the James River and Rivanna River–Stigger Creek, where a few sand dikes were found in the 1990s. Liquefaction features are grouped into two age categories based on dating of host sediment in which they occur and weathering characteristics of the features. A younger generation of features that formed during the past 350 yr are small, few in number, and appear to be limited to the James and Pamunkey Rivers. Though there are large uncertainties in their locations and magnitudes, one or more preinstrumental earthquakes, including the 1758, 1774, and 1875 events, likely caused these features. An older generation of liquefaction features that formed between 350 and 2800 yr ago are larger, more numerous, and more broadly distributed than the younger generation of features. Several earthquakes could account for the regional distribution of paleoliquefaction features, including one event of M "> M M 6.25–6.5 near Holly Grove, or two events of M "> M M 6.0 near Mineral and M "> M M 6.25 near Ashland. Amplification of ground motions in Coastal Plain sediment might have contributed to liquefaction along the Mattaponi and Pamunkey Rivers.

Seismological Research Letters↗

USGS2016

Preliminary assessment of a previously unknown fault zone beneath the Daytona Beach sand blow cluster near Marianna, Arkansas

We collected new high‐resolution P ‐wave seismic‐reflection data to explore for possible faults beneath a roughly linear cluster of early to mid‐Holocene earthquake‐induced sand blows to the south of Marianna, Arkansas. The Daytona Beach sand blow deposits are located in east‐central Arkansas about 75 km southwest of Memphis, Tennessee, and about 80 km south of the southwestern end of the New Madrid seismic zone (NMSZ). Previous studies of these sand blows indicate that they were produced between 10,500 and 5350 yr B.P. (before A.D. 1950). The sand blows are large and similar in size to those in the heart of the NMSZ produced by the 1811–1812 earthquakes. The seismic‐reflection profiles reveal a previously unknown zone of near‐vertical faults imaged in the 100–1100‐m depth range that are approximately coincident with a cluster of earthquake‐induced sand blows and a near‐linear surface lineament composed of air photo tonal anomalies. These interpreted faults are expressed as vertical discontinuities with the largest displacement fault showing about 40 m of west‐side‐up displacement at the top of the Paleozoic section at about 1100 m depth. There are about 20 m of folding on reflections within the Eocene strata at 400 m depth. Increasing fault displacement with depth suggests long‐term recurrent faulting. The imaged faults within the vicinity of the numerous sand blow features could be a causative earthquake source, although it does not rule out the possibility of other seismic sources nearby. These newly located faults add to a growing list of potentially active Pleistocene–Holocene faults discovered over the last two decades that are within the Mississippi embayment region but outside of the historical NMSZ.

Arkansas↗

USGS2015

Geotechnical aspects in the epicentral region of the 2011, M w 5.8 Mineral, Virginia earthquake

A reconnaissance team documented the geotechnical and geological aspects in the epicentral region of the M w (moment magnitude) 5.8 Mineral, Virginia (USA), earthquake of 23 August 2011. Tectonically and seismically induced ground deformations, evidence of liquefaction, rock slides, river bank slumps, ground subsidence, performance of earthen dams, damage to public infrastructure and lifelines, and other effects of the earthquake were documented. This moderate earthquake provided the rare opportunity to collect data to help assess current geoengineering practices in the region, as well as to assess seismic performance of the aging infrastructure in the region. Ground failures included two marginal liquefaction sites, a river bank slump, four minor rockfalls, and a ~4-m-wide, ~12-m-long, ~0.3-m-deep subsidence on a residential property. Damage to lifelines included subsidence of the approaches for a bridge and a water main break to a heavily corroded, 5-cm-diameter valve in Mineral, Virginia. Observed damage to dams, landfills, and public-use properties included a small, shallow slide in the temporary (“working”) clay cap of the county landfill, damage to two earthen dams (one in the epicentral region and one further away near Bedford, Virginia), and substantial structural damage to two public school buildings.

Virginia↗

USGS2014

Effects of 2010 Hurricane Earl amidst geologic evidence for greater overwash at Anegada, British Virgin Islands

A post-hurricane survey of a Caribbean island affords comparisons with geologic evidence for greater overwash at the same place. This comparison, though of limited application to other places, helps calibrate coastal geology for assessment of earthquake and tsunami potential along the Antilles Subduction Zone. The surveyed island, Anegada, is 120 km south of the Puerto Rico Trench and is near the paths of hurricanes Donna (1960) and Earl (2010), which were at or near category 4 when at closest approach. The survey focused on Earl's geologic effects, related them to the surge from Hurricane Donna, and compared them further with erosional and depositional signs of southward overwash from the Atlantic Ocean that dates to 1200–1450 AD and to 1650–1800 AD. The main finding is that the geologic effects of these earlier events dwarf those of the recent hurricanes. Hurricane Earl's geologic effects at Anegada, observed mainly in 2011, were limited to wrack deposition along many of the island's shores and salt ponds, accretion of small washover (spillover) fans on the south shore, and the suspension and deposition of microbial material from interior salt ponds. Earl's most widespread deposit at Anegada, the microbial detritus, was abundantly juxtaposed with evidence for catastrophic overwash in prior centuries. The microbial detritus formed an extensive coating up to 2 cm thick that extended into breaches in beach-ridge plains of the island's north shore, onto playas that are underlain by a sand-and-shell sheet that extends as much as 1.5 km southward from the north shore, and among southward-strewn limestone boulders pendant to outcrops as much as 1 km inland. Earl's spillover fans also contrast with a sand-and-shell sheet, which was dated previously to 1650–1800, by being limited to the island's south shore and by extending inland a few tens of meters at most. These findings complement those reported in this issue by Michaela Spiske and Robert Halley (Spiske and Halley, 2014), who studied a coral-rubble ridge that lines part of Anegada's north shore. Spiske and Halley attribute the ridge to storms that were larger than Earl. But they contrast the ridge with coral boulders that were scattered hundreds of meters inland by overwash in 1200–1450.

Anegada↗

USGS2005

Liquefaction induced by historic and prehistoric earthquakes in western Puerto Rico

Dozens of liquefaction features in western Puerto Rico probably formed during at least three large earthquakes since A.D. 1300. Many of the features formed during the 1918 moment magnitude (M) 7.3 event and the 1670 event, which may have been as large as M 7 and centered in the Añasco River Valley. Liquefaction features along Río Culebrinas, and possibly a few along Río Grande de Añasco, appear to have formed ca. A.D. 1300–1508 as the result of a M ≥ 6.5 earthquake. We conducted reconnaissance along Río Culebrinas, Río Grande de Añasco, and Río Guanajibo, where we found and studied numerous liquefaction features, dated organic samples occurring in association with liquefaction features, and performed liquefaction potential analysis with geotechnical data previously collected along the three rivers. Our ongoing study will provide additional information regarding the age and size distribution of liquefaction features along the western, northern, and eastern coasts and will help to improve estimates of the timing, source areas, and magnitudes of earthquakes that struck Puerto Rico during the late Holocene.

Añasco River Valley, Río Culebrinas, Río Grande de↗

USGS2002

The earthquake potential of the New Madrid seismic zone

The fault system responsible for New Madrid seismicity has generated temporally clustered very large earthquakes in A.D. 900 ± 100 years and A.D. 1450 ± 150 years as well as in 1811–1812. Given the uncertainties in dating liquefaction features, the time between the past three New Madrid events may be as short as 200 years and as long as 800 years, with an average of 500 years. This advance in understanding the Late Holocene history of the New Madrid seismic zone and thus, the contemporary tectonic behavior of the associated fault system was made through studies of hundreds of earthquake-induced liquefaction features at more than 250 sites across the New Madrid region. We have found evidence that prehistoric sand blows, like those that formed during the 1811–1812 earthquakes, are probably compound structures resulting from multiple earthquakes closely clustered in time or earthquake sequences. From the spatial distribution and size of sand blows and their sedimentary units, we infer the source zones and estimate the magnitudes of earthquakes within each sequence and thereby characterize the detailed behavior of the fault system. It appears that fault rupture was complex and that the central branch of the seismic zone produced very large earthquakes during the A.D. 900 and A.D. 1450 events as well as in 1811–1812. On the basis of a minimum recurrence rate of 200 years, we are now entering the period during which the next 1811–1812-type event could occur.

Arkansas, Kentucky, Missouri, Tennessee↗

USGS1996

Use of archaeology to date liquefaction features and seismic events in the New Madrid seismic zone, Central United States

Prehistoric earthquake-induced liquefaction features occur in association with Native American occupation horizons in the New Madrid seismic zone. Age control of these liquefaction features, including sand-blow deposits, sand-blow craters, and sand dikes, can be accomplished by extensive sampling and flotation processing of datable materials as well as archaeobotanical analysis of associated archaeological horizons and pits. This approach increases both the amount of carbon for radiocarbon dating and the precision dating of artifact assemblages. Using this approach, we dated liquefaction features at four sites northwest of Blytheville, Arkansas, and found that at least one significant earthquake occurred in the New Madrid seismic zone between A.D. 1180 and 1400, probably about A.D. 1300 ± 100 yr. In addition, we found three buried sand blows that formed between 3340 B.C. and A.D. 780. In this region where very large to great earthquakes appear to be closely timed, archaeology is helping to develop a paleoearthquake chronology for the New Madrid seismic zone.

Arkansas, Kentucky, Missouri, Tennessee↗