The Liquefaction Model
The 2010 M7.1 Darfield earthquake in
New Zealand started a sequence of events – the Canterbury Earthquake Sequence
(CES), that propagated eastward in the Canterbury region over several years. Since
the City of Christchurch is built on alluvial sediments where the water table
is very shallow, several of the larger events created widespread liquefaction
within the city and surrounding areas. Such ground deformations caused a
significant number of buildings with shallow foundations to settle, tilt and
Prior to these New Zealand earthquakes, liquefaction was observed but not on this scale in a built-up area in a developed country. As in previous well-studied liquefaction events (e.g. 1964 Niigata) this was a unique opportunity to examine liquefaction severity and building responses. Christchurch was referred to as a “liquefaction laboratory” with the multiple events causing different levels of shaking across the city. However, we had not previously seen suburbs of insured buildings damaged by liquefaction.
The Source Model
The 2010 M7.1 Darfield earthquake in
New Zealand started a sequence of events that propagated eastward in the
Canterbury region over several years, collectively causing upward of 15
individual loss-causing events for the insurance industry. The Insurance
Council of New Zealand state that the total insured loss was more than NZ$31
billion (US$19.4 billion).
With such a significant sequence of events, a lot had to be learned and reflected into earthquake risk modeling, both to be scientifically robust and to answer the new regulatory needs. GNS Science – the New Zealand Crown Research Institute, had issued its National Seismic Hazard Model (NSHM) in 2010, before the Canterbury Earthquake Sequence (CES) and before Tōhoku. The model release was a major project, and at the time, in response to the CES, GNS only had the bandwidth for a mini-update to the 2010 models, to allow M9 events on the Hikurangi Subduction Interface, New Zealand’s largest plate boundary fault, and to get a working group started on Canterbury earthquake rates.
But given the high penetration rate of earthquake insurance in New Zealand and the magnitude of the damage in the Canterbury region, the (re)insurance and regulatory position was in transition. Rather than wait for a new National Seismic Hazard Map (NSHMP) update (which is still in not available), RMS joined the national effort and started a collaboration with GNS Science as well as our own research, to build a model that would help during this difficult time, when many rebuild decisions had to be made. The RMS® New Zealand Earthquake High Definition (HD) model was released in mid-2016.
A few hundred yards from where Stephen Hawking first explored black holes from his wheelchair, is the Institute of Criminology at the University of Cambridge. Hawking never shied away from really hard problems; nor do the Cambridge criminologists. There is no Nobel Prize for finding viable solutions to rehabilitating prisoners, but the Cambridge Learning Together program has forged new communal pathways for addressing this major societal challenge. The program seeks to bring together people in criminal justice and higher education institutions to study alongside each other in inclusive and transformative learning communities.
The Learning Together program began at the University of Cambridge in 2014, in partnership with HMP Grendon, a small prison at a village named Grendon Underwood, outside London. This program recognizes that collaboration underpins the growth of opportunities for the learning progression of students in prison, and the development of pathways towards non-offending futures.
Five years on, a celebration alumni event was organized for Black Friday, November 29. This took place in the City of London, at Fishmongers’ Hall, off London Bridge. This happens to be close to the Monument, where the RMS London office is situated.